研究者情報

マスター

アカウント（マスター）

• 氏名

  藤間　憲幸(フジマ　ノリユキ), フジマ　ノリユキ

所属（マスター）

• 北海道大学病院　放射線科

所属（マスター）

• 北海道大学病院　放射線科

独自項目

syllabus

• 2021, 基本医学総論, Basic Principles of Medicine, 修士課程, 医学院, 画像診断、CT、MRI、PET、SPECT、血管造影、超音波、IVR、RI内用療法
• 2021, 医学総論, Principles of Medicine, 博士後期課程, 医学院, 画像診断、CT、MRI、PET、SPECT、血管造影、超音波、IVR、RI内用療法

researchmap

プロフィール情報

学位

• 博士（医学）（北海道大学）

プロフィール情報

• 姓

  藤間, フジマ

• 名

  憲幸, ノリユキ

• ID各種

  201501011677390619

業績リスト

研究キーワード

• MRI   腫瘍血流   癌   磁気共鳴画像   解析学   頭頸部扁平上皮癌   画像   頭頸部腫瘍   腫瘍増殖能   低酸素   頭頸部癌   拡散強調像   QSI   

研究分野

• ライフサイエンス / 放射線科学
• ライフサイエンス / 病態系口腔科学

経歴

• 2020年07月 - 現在 北海道大学 大学病院 講師

論文

• Enhancing the image quality of prostate diffusion-weighted imaging in patients with prostate cancer through model-based deep learning reconstruction.

  Noriko Nishioka, Noriyuki Fujima, Satonori Tsuneta, Masato Yoshikawa, Rina Kimura, Keita Sakamoto, Fumi Kato, Haruka Miyata, Hiroshi Kikuchi, Ryuji Matsumoto, Takashige Abe, Jihun Kwon, Masami Yoneyama, Kohsuke Kudo

  European journal of radiology open 13 100588 - 100588 2024年12月 

  PURPOSE: To evaluate the utility of model-based deep learning reconstruction in prostate diffusion-weighted imaging (DWI). METHODS: This retrospective study evaluated two prostate diffusion-weighted imaging (DWI) methods: deep learning reconstruction (DL-DWI) and traditional parallel imaging (PI-DWI). We examined 32 patients with radiologically diagnosed and histologically confirmed prostate cancer (PCa) lesions ≥10 mm. Image quality was evaluated both qualitatively (for overall quality, prostate conspicuity, and lesion conspicuity) and quantitatively, using the signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and apparent diffusion coefficient (ADC) for prostate tissue. RESULTS: In the qualitative evaluation, DL-DWI scored significantly higher than PI-DWI for all three parameters (p<0.0001). In the quantitative analysis, DL-DWI showed significantly higher SNR and CNR values compared to PI-DWI (p<0.0001). Both the prostate tissue and the lesions exhibited significantly higher ADC values in DL-DWI compared to PI-DWI (p<0.0001, p=0.0014, respectively). CONCLUSION: Model-based DL reconstruction enhanced both qualitative and quantitative aspects of image quality in prostate DWI. However, this study did not include comparisons with other DL-based methods, which is a limitation that warrants future research.
• Advancing clinical MRI exams with artificial intelligence: Japan’s contributions and future prospects

  Shohei Fujita, Yasutaka Fushimi, Rintaro Ito, Yusuke Matsui, Fuminari Tatsugami, Tomoyuki Fujioka, Daiju Ueda, Noriyuki Fujima, Kenji Hirata, Takahiro Tsuboyama, Taiki Nozaki, Masahiro Yanagawa, Koji Kamagata, Mariko Kawamura, Akira Yamada, Takeshi Nakaura, Shinji Naganawa

  Japanese Journal of Radiology 2024年11月16日 

  Abstract In this narrative review, we review the applications of artificial intelligence (AI) into clinical magnetic resonance imaging (MRI) exams, with a particular focus on Japan’s contributions to this field. In the first part of the review, we introduce the various applications of AI in optimizing different aspects of the MRI process, including scan protocols, patient preparation, image acquisition, image reconstruction, and postprocessing techniques. Additionally, we examine AI’s growing influence in clinical decision-making, particularly in areas such as segmentation, radiation therapy planning, and reporting assistance. By emphasizing studies conducted in Japan, we highlight the nation’s contributions to the advancement of AI in MRI. In the latter part of the review, we highlight the characteristics that make Japan a unique environment for the development and implementation of AI in MRI examinations. Japan’s healthcare landscape is distinguished by several key factors that collectively create a fertile ground for AI research and development. Notably, Japan boasts one of the highest densities of MRI scanners per capita globally, ensuring widespread access to the exam. Japan’s national health insurance system plays a pivotal role by providing MRI scans to all citizens irrespective of socioeconomic status, which facilitates the collection of inclusive and unbiased imaging data across a diverse population. Japan’s extensive health screening programs, coupled with collaborative research initiatives like the Japan Medical Imaging Database (J-MID), enable the aggregation and sharing of large, high-quality datasets. With its technological expertise and healthcare infrastructure, Japan is well-positioned to make meaningful contributions to the MRI–AI domain. The collaborative efforts of researchers, clinicians, and technology experts, including those in Japan, will continue to advance the future of AI in clinical MRI, potentially leading to improvements in patient care and healthcare efficiency.
• Applications of artificial intelligence in interventional oncology: An up-to-date review of the literature.

  Yusuke Matsui, Daiju Ueda, Shohei Fujita, Yasutaka Fushimi, Takahiro Tsuboyama, Koji Kamagata, Rintaro Ito, Masahiro Yanagawa, Akira Yamada, Mariko Kawamura, Takeshi Nakaura, Noriyuki Fujima, Taiki Nozaki, Fuminari Tatsugami, Tomoyuki Fujioka, Kenji Hirata, Shinji Naganawa

  Japanese journal of radiology 2024年10月02日 

  Interventional oncology provides image-guided therapies, including transarterial tumor embolization and percutaneous tumor ablation, for malignant tumors in a minimally invasive manner. As in other medical fields, the application of artificial intelligence (AI) in interventional oncology has garnered significant attention. This narrative review describes the current state of AI applications in interventional oncology based on recent literature. A literature search revealed a rapid increase in the number of studies relevant to this topic recently. Investigators have attempted to use AI for various tasks, including automatic segmentation of organs, tumors, and treatment areas; treatment simulation; improvement of intraprocedural image quality; prediction of treatment outcomes; and detection of post-treatment recurrence. Among these, the AI-based prediction of treatment outcomes has been the most studied. Various deep and conventional machine learning algorithms have been proposed for these tasks. Radiomics has often been incorporated into prediction and detection models. Current literature suggests that AI is potentially useful in various aspects of interventional oncology, from treatment planning to post-treatment follow-up. However, most AI-based methods discussed in this review are still at the research stage, and few have been implemented in clinical practice. To achieve widespread adoption of AI technologies in interventional oncology procedures, further research on their reliability and clinical utility is necessary. Nevertheless, considering the rapid research progress in this field, various AI technologies will be integrated into interventional oncology practices in the near future.
• Generative AI and large language models in nuclear medicine: current status and future prospects.

  Kenji Hirata, Yusuke Matsui, Akira Yamada, Tomoyuki Fujioka, Masahiro Yanagawa, Takeshi Nakaura, Rintaro Ito, Daiju Ueda, Shohei Fujita, Fuminari Tatsugami, Yasutaka Fushimi, Takahiro Tsuboyama, Koji Kamagata, Taiki Nozaki, Noriyuki Fujima, Mariko Kawamura, Shinji Naganawa

  Annals of nuclear medicine 2024年09月25日 

  This review explores the potential applications of Large Language Models (LLMs) in nuclear medicine, especially nuclear medicine examinations such as PET and SPECT, reviewing recent advancements in both fields. Despite the rapid adoption of LLMs in various medical specialties, their integration into nuclear medicine has not yet been sufficiently explored. We first discuss the latest developments in nuclear medicine, including new radiopharmaceuticals, imaging techniques, and clinical applications. We then analyze how LLMs are being utilized in radiology, particularly in report generation, image interpretation, and medical education. We highlight the potential of LLMs to enhance nuclear medicine practices, such as improving report structuring, assisting in diagnosis, and facilitating research. However, challenges remain, including the need for improved reliability, explainability, and bias reduction in LLMs. The review also addresses the ethical considerations and potential limitations of AI in healthcare. In conclusion, LLMs have significant potential to transform existing frameworks in nuclear medicine, making it a critical area for future research and development.
• Accelerating FLAIR imaging via deep learning reconstruction: potential for evaluating white matter hyperintensities.

  Noriko Nishioka, Yukie Shimizu, Yukio Kaneko, Toru Shirai, Atsuro Suzuki, Tomoki Amemiya, Hisaaki Ochi, Yoshitaka Bito, Masahiro Takizawa, Yohei Ikebe, Hiroyuki Kameda, Taisuke Harada, Noriyuki Fujima, Kohsuke Kudo

  Japanese journal of radiology 2024年09月24日 

  PURPOSE: To evaluate deep learning-reconstructed (DLR)-fluid-attenuated inversion recovery (FLAIR) images generated from undersampled data, compare them with fully sampled and rapidly acquired FLAIR images, and assess their potential for white matter hyperintensity evaluation. MATERIALS AND METHODS: We examined 30 patients with white matter hyperintensities, obtaining fully sampled FLAIR images (standard FLAIR, std-FLAIR). We created accelerated FLAIR (acc-FLAIR) images using one-third of the fully sampled data and applied deep learning to generate DLR-FLAIR images. Three neuroradiologists assessed the quality (amount of noise and gray/white matter contrast) in all three image types. The reproducibility of hyperintensities was evaluated by comparing a subset of 100 hyperintensities in acc-FLAIR and DLR-FLAIR images with those in the std-FLAIR images. Quantitatively, similarities and errors of the entire image and the focused regions on white matter hyperintensities in acc-FLAIR and DLR-FLAIR images were measured against std-FLAIR images using structural similarity index measure (SSIM), regional SSIM, normalized root mean square error (NRMSE), and regional NRMSE values. RESULTS: All three neuroradiologists evaluated DLR-FLAIR as having significantly less noise and higher image quality scores compared with std-FLAIR and acc-FLAIR (p < 0.001). All three neuroradiologists assigned significantly higher frontal lobe gray/white matter visibility scores for DLR-FLAIR than for acc-FLAIR (p < 0.001); two neuroradiologists attributed significantly higher scores for DLR-FLAIR than for std-FLAIR (p < 0.05). Regarding white matter hyperintensities, all three neuroradiologists significantly preferred DLR-FLAIR (p < 0.0001). DLR-FLAIR exhibited higher similarity to std-FLAIR in terms of visibility of the hyperintensities, with 97% of the hyperintensities rated as nearly identical or equivalent. Quantitatively, DLR-FLAIR demonstrated significantly higher SSIM and regional SSIM values than acc-FLAIR, with significantly lower NRMSE and regional NRMSE values (p < 0.0001). CONCLUSIONS: DLR-FLAIR can reduce scan time and generate images of similar quality to std-FLAIR in patients with white matter hyperintensities. Therefore, DLR-FLAIR may serve as an effective method in traditional magnetic resonance imaging protocols.
• Recent trends in AI applications for pelvic MRI: a comprehensive review

  Takahiro Tsuboyama, Masahiro Yanagawa, Tomoyuki Fujioka, Shohei Fujita, Daiju Ueda, Rintaro Ito, Akira Yamada, Yasutaka Fushimi, Fuminari Tatsugami, Takeshi Nakaura, Taiki Nozaki, Koji Kamagata, Yusuke Matsui, Kenji Hirata, Noriyuki Fujima, Mariko Kawamura, Shinji Naganawa

  La radiologia medica 2024年08月03日
• High Resolution TOF-MRA Using Compressed Sensing-based Deep Learning Image Reconstruction for the Visualization of Lenticulostriate Arteries: A Preliminary Study.

  Yuya Hirano, Noriyuki Fujima, Hiroyuki Kameda, Kinya Ishizaka, Jihun Kwon, Masami Yoneyama, Kohsuke Kudo

  Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 2024年07月20日 

  PURPOSE: To investigate the visibility of the lenticulostriate arteries (LSAs) in time-of-flight (TOF)-MR angiography (MRA) using compressed sensing (CS)-based deep learning (DL) image reconstruction by comparing its image quality with that obtained by the conventional CS algorithm. METHODS: Five healthy volunteers were included. High-resolution TOF-MRA images with the reduction (R)-factor of 1 were acquired as full-sampling data. Images with R-factors of 2, 4, and 6 were then reconstructed using CS-DL and conventional CS (the combination of CS and sensitivity conceding; CS-SENSE) reconstruction, respectively. In the quantitative assessment, the number of visible LSAs (identified by two radiologists), length of each depicted LSA (evaluated by one radiological technologist), and normalized mean squared error (NMSE) value were assessed. In the qualitative assessment, the overall image quality and the visibility of the peripheral LSA were visually evaluated by two radiologists. RESULTS: In the quantitative assessment of the DL-CS images, the number of visible LSAs was significantly higher than those obtained with CS-SENSE in the R-factors of 4 and 6 (Reader 1) and in the R-factor of 6 (Reader 2). The length of the depicted LSAs in the DL-CS images was significantly longer in the R-factor 6 compared to the CS-SENSE result. The NMSE value in CS-DL was significantly lower than in CS-SENSE for R-factors of 4 and 6. In the qualitative assessment of DL-CS images, the overall image quality was significantly higher than that obtained with CS-SENSE in the R-factors 4 and 6 (Reader 1) and in the R-factor 4 (Reader 2). The visibility of the peripheral LSA was significantly higher than that shown by CS-SENSE in all R-factors (Reader 1) and in the R-factors 2 and 4 (Reader 2). CONCLUSION: CS-DL reconstruction demonstrated preserved image quality for the depiction of LSAs compared to the conventional CS-SENSE when the R-factor is elevated.
• Optimal catheter selection for acute stroke patients with type III aortic arch based on magnetic resonance angiography road mapping of the para-aortic trans-femoral access route before mechanical thrombectomy.

  Satoshi Kobayashi, Toshiya Osanai, Noriyuki Fujima, Akiyoshi Hamaguchi, Taku Sugiyama, Toshitaka Nakamura, Kazutoshi Hida, Hiroyuki Itosaka, Yoshimasa Niiya, Miki Fujimura

  World neurosurgery 2024年07月16日 

  BACKGROUND: Although mechanical thrombectomy for acute ischemic stroke has a high recanalization rate, procedurally challenging lesions remain in approximately 10% of the cases. Type III aortic arches, due to their anatomical configuration, are a fundamental problem impacting this procedure. This study aimed to determine whether optimal catheter selection for type III aortic arches, using magnetic resonance angiography (MRA)-based road mapping of the para-aortic transfemoral access route, reduces the time required for mechanical thrombectomy. METHODS: We retrospectively evaluated 203 consecutive patients who underwent mechanical thrombectomy at multiple centers between April 2018 and July 2022. Twenty-three patients were diagnosed with a type III aortic arch using MRA-based road mapping performed to visualize the para-aortic access route before neuro-interventional procedures. Among the 23 patients with type III aortic arches, 10 received a Simmons-type catheter (initial Simmons group) and 13 received a JB-2-type catheter® (initial JB-2 group) as their first inner catheter. The time required for mechanical thrombectomy was compared between the groups. RESULTS: Compared with the initial JB-2 group, the initial Simmons group exhibited a significantly shorter "puncture-to-recanalization time" (105 vs. 53 min, p = 0.009) and "door-to-recanalization time" (164 vs. 129 min, p = 0.032). CONCLUSIONS: Optimal catheter selection by identifying the aortic arch before mechanical thrombectomy using MRA-based road mapping effectively reduced the mechanical thrombectomy time. This suggests that even in type III aorta cases, appropriate catheter selection may shorten the mechanical thrombectomy time and improve acute ischemic stroke prognosis.
• Climate change and artificial intelligence in healthcare: Review and recommendations towards a sustainable future

  Daiju Ueda, Shannon L Walston, Shohei Fujita, Yasutaka Fushimi, Takahiro Tsuboyama, Koji Kamagata, Akira Yamada, Masahiro Yanagawa, Rintaro Ito, Noriyuki Fujima, Mariko Kawamura, Takeshi Nakaura, Yusuke Matsui, Fuminari Tatsugami, Tomoyuki Fujioka, Taiki Nozaki, Kenji Hirata, Shinji Naganawa

  Diagnostic and Interventional Imaging 2024年06月
• Predictive value of the hemispheric magnetic resonance angiography score on the development of indirect pial synangiosis after combined revascularization surgery for adult moyamoya disease.

  Haruto Uchino, Masaki Ito, Noriyuki Fujima, Kikutaro Tokairin, Ryota Tatezawa, Taku Sugiyama, Miki Fujimura

  Acta neurochirurgica 166 1 181 - 181 2024年04月17日 

  PURPOSE: It is difficult to precisely predict indirect bypass development in the context of combined bypass procedures in moyamoya disease (MMD). We aimed to investigate the predictive value of magnetic resonance angiography (MRA) signal intensity in the peripheral portion of the major cerebral arteries for indirect bypass development in adult patients with MMD. METHODS: We studied 93 hemispheres from 62 adult patients who underwent combined direct and indirect revascularization between 2005 and 2019 and genetic analysis for RNF213 p.R4810K. The signal intensity of the peripheral portion of the major intracranial arteries during preoperative MRA was graded as a hemispheric MRA score (0-3 in the middle cerebral artery and 0-2 in the anterior cerebral and posterior cerebral arteries, with a high score representing low visibility) according to each vessel's visibility. Postoperative bypass development was qualitatively evaluated using MRA, and we evaluated the correlation between preoperative factors, including the hemispheric MRA score and bypass development, using univariate and multivariate analyses. RESULTS: A good indirect bypass was observed in 70% of the hemispheres. Hemispheric MRA scores were significantly higher in hemispheres with good indirect bypass development than in those with poor indirect bypass development (median: 3 vs. 1; p < 0.0001). Multiple logistic regression analysis revealed hemispheric MRA score as an independent predictor of good indirect bypass development (odds ratio, 2.1; 95% confidence interval, 1.3-3.6; p < 0.01). The low hemispheric MRA score (< 2) and wild-type RNF213 predicted poor indirect bypass development with a specificity of 0.92. CONCLUSION: Hemispheric MRA score was a predictive factor for indirect bypass development in adult patients who underwent a combined bypass procedure for MMD. Predicting poor indirect bypass development may lead to future tailored bypass surgeries for MMD.
• Comparison of Echo-Planar Imaging and Compressed Sensing in the Estimation of Flow Metrics from Aortic 4D Flow MR Imaging: A Healthy Volunteer Study.

  Satoru Aono, Satonori Tsuneta, Noriko Nishioka, Takuya Aoike, Hiroyuki Hirayama, Kinya Ishizaka, Jihun Kwon, Masami Yoneyama, Noriyuki Fujima, Kohsuke Kudo

  Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 2024年03月29日 

  PURPOSE: Prolonged scanning of time-resolved 3D phase-contrast MRI (4D flow MRI) limits its routine use in clinical practice. An echo-planar imaging (EPI)-based sequence and compressed sensing can reduce the scan duration. We aimed to determine the impact of EPI for 4D flow MRI on the scan duration, image quality, and quantitative flow metrics. METHODS: This was a prospective study of 15 healthy volunteers (all male, mean age 33 ± 5 years). Conventional sensitivity encoding (SENSE), EPI with SENSE (EPI), and compressed SENSE (CS) (reduction factors: 6 and 12, respectively) were scanned.Scan duration, qualitative indexes of image quality, and quantitative flow parameters of net flow volume, maximum flow velocity, wall shear stress (WSS), and energy loss (EL) in the ascending aorta were assessed. Two-dimensional phase-contrast cine MRI (2D-PC) was considered the gold standard of net flow volume and maximum flow velocity. RESULTS: Compared to SENSE, EPI and CS12 shortened scan durations by 71% and 73% (EPI, 4 min 39 sec; CS6, 7 min 29 sec; CS12, 4 min 14 sec; and SENSE, 15 min 51 sec). Visual image quality was significantly better for EPI than for SENSE and CS (P < 0.001). The net flow volumes obtained with SENSE, EPI, and CS12 and those obtained with 2D-PC were correlated well (r = 0.950, 0.871, and 0.850, respectively). However, the maximum velocity obtained with EPI was significantly underestimated (P < 0.010). The average WSS was significantly higher with EPI than with SENSE, CS6, and CS12 (P < 0.001, P = 0.040, and P = 0.012, respectively). The EL was significantly lower with EPI than with CS6 and CS12 (P = 0.002 and P = 0.007, respectively). CONCLUSION: EPI reduced the scan duration, improved visual image quality, and was associated with more accurate net flow volume than CS. However, the flow velocity, WSS, and EL values obtained with EPI and other sequences may not be directly comparable.
• The impact of large language models on radiology: a guide for radiologists on the latest innovations in AI.

  Takeshi Nakaura, Rintaro Ito, Daiju Ueda, Taiki Nozaki, Yasutaka Fushimi, Yusuke Matsui, Masahiro Yanagawa, Akira Yamada, Takahiro Tsuboyama, Noriyuki Fujima, Fuminari Tatsugami, Kenji Hirata, Shohei Fujita, Koji Kamagata, Tomoyuki Fujioka, Mariko Kawamura, Shinji Naganawa

  Japanese journal of radiology 2024年03月29日 

  The advent of Deep Learning (DL) has significantly propelled the field of diagnostic radiology forward by enhancing image analysis and interpretation. The introduction of the Transformer architecture, followed by the development of Large Language Models (LLMs), has further revolutionized this domain. LLMs now possess the potential to automate and refine the radiology workflow, extending from report generation to assistance in diagnostics and patient care. The integration of multimodal technology with LLMs could potentially leapfrog these applications to unprecedented levels.However, LLMs come with unresolved challenges such as information hallucinations and biases, which can affect clinical reliability. Despite these issues, the legislative and guideline frameworks have yet to catch up with technological advancements. Radiologists must acquire a thorough understanding of these technologies to leverage LLMs' potential to the fullest while maintaining medical safety and ethics. This review aims to aid in that endeavor.
• MELASに類似した脳卒中様発作を生じた神経核内封入体病の1例

  亀田 浩之, 原田 太以佑, 藤間 憲幸, 清水 幸衣, 池辺 洋平, 平田 健司, 矢部 一郎, 工藤 與亮

  北海道放射線医学雑誌 4 20 - 24 (NPO)メディカルイメージラボ 2024年03月 

  症例は70歳代女性。約5年前に脳炎・脳症症状のため受診し、皮膚・直腸生検にて神経核内封入体病と診断された。今回、左上下肢麻痺で当院救急搬送となった。入院時の頭部MRIでは、拡散強調画像で右頭頂後頭葉から側頭葉の皮質下白質に高信号が出現した。MRAでは右中・後大脳動脈に拡張所見を認めた。ASLと脳血流IMP-SPECTでは、右頭頂後頭葉から側頭葉にかけて広範な過灌流を認め、造影MRIでは同領域の皮質に沿った増強効果を認めた。痙攣後脳症とNIIDに伴うMELAS様の急性脳症が鑑別疾患に挙がったが、拡散強調像での皮髄境界優位の分布と大脳皮質の増強効果、ステロイドパルス療法後の臨床症状や画像所見の経過から、MELAS様の急性脳症を呈したNIIDと診断した。NIIDの症状は多彩であるが、一部の患者でMELASに類似した臨床症状と画像所見を示す症例が近年報告されており、NIID患者の脳卒中様の発症様式とその画像所見の特徴を知っておく必要がある。(著者抄録)
• Increased CD44 expression in primary meningioma: its clinical significance and association with peritumoral brain edema.

  Ryosuke Sawaya, Shigeru Yamaguchi, Yukitomo Ishi, Michinari Okamoto, Sumire Echizenya, Hiroaki Motegi, Noriyuki Fujima, Miki Fujimura

  Journal of neurosurgery 1 - 8 2024年02月09日 

  OBJECTIVE: CD44 is a major cell surface receptor involved in cell adhesion and migration. The overexpression of CD44 is a poor prognostic factor in many neoplasms, including meningiomas. The aim of this study was to investigate the association between CD44 gene expression and clinical signatures of primary meningiomas. METHODS: CD44 gene expression was quantitatively evaluated by snap freezing tumor tissues obtained from 106 patients with primary meningioma. The relationships between CD44 expression and clinical signatures of meningiomas, including histological malignancy, tumor volume, and peritumoral brain edema (PTBE), were analyzed. PTBE was assessed using the Steinhoff classification (SC) system (from SC 0 to SC III). RESULTS: CD44 gene expression in WHO grade 2 and 3 meningiomas was significantly higher than that in grade 1 meningiomas. In addition, CD44 expression increased with the severity of PTBE. Particularly, among the grade 1 meningiomas or small-sized tumors (maximum tumor diameter < 43 mm), CD44 expression in tumors with severe PTBE (SC II or III) was significantly higher than that in tumors without or with mild PTBE (SC 0 or I). Multivariate logistic regression analysis also revealed that overexpression of CD44 was an independent significant factor of severe PTBE development in primary meningiomas. CONCLUSIONS: In addition to tumor cell aggressiveness, CD44 expression promotes the development of PTBE in meningioma. Since PTBE is a strong factor of tumor-related epilepsy or cognitive dysfunction in patients with meningioma, CD44 is thus a potential therapeutic target in meningioma with PTBE.
• Improved image quality in contrast-enhanced 3D-T1 weighted sequence by compressed sensing-based deep-learning reconstruction for the evaluation of head and neck.

  Noriyuki Fujima, Junichi Nakagawa, Yohei Ikebe, Hiroyuki Kameda, Taisuke Harada, Yukie Shimizu, Nayuta Tsushima, Satoshi Kano, Akihiro Homma, Jihun Kwon, Masami Yoneyama, Kohsuke Kudo

  Magnetic resonance imaging 108 111 - 115 2024年02月09日 

  PURPOSE: To assess the utility of deep learning (DL)-based image reconstruction with the combination of compressed sensing (CS) denoising cycle by comparing images reconstructed by conventional CS-based method without DL in fat-suppressed (Fs)-contrast enhanced (CE) three-dimensional (3D) T1-weighted images (T1WIs) of the head and neck. MATERIALS AND METHODS: We retrospectively analyzed the cases of 39 patients who had undergone head and neck Fs-CE 3D T1WI applying reconstructions based on conventional CS and CS augmented by DL, respectively. In the qualitative assessment, we evaluated overall image quality, visualization of anatomical structures, degree of artifacts, lesion conspicuity, and lesion edge sharpness based on a five-point system. In the quantitative assessment, we calculated the signal-to-noise ratios (SNRs) of the lesion and the posterior neck muscle and the contrast-to-noise ratio (CNR) between the lesion and the adjacent muscle. RESULTS: For all items of the qualitative analysis, significantly higher scores were awarded to images with DL-based reconstruction (p < 0.001). In the quantitative analysis, DL-based reconstruction resulted in significantly higher values for both the SNR of lesions (p < 0.001) and posterior neck muscles (p < 0.001). Significantly higher CNRs were also observed in images with DL-based reconstruction (p < 0.001). CONCLUSION: DL-based image reconstruction integrating into the CS-based denoising cycle offered superior image quality compared to the conventional CS method. This technique will be useful for the assessment of patients with head and neck disease.
• 内耳に造影効果を認めたCogan症候群の1例

  小市 裕太, 池辺 洋平, 藤間 憲幸, 亀田 浩之, 原田 太以佑, 清水 幸衣, 工藤 與亮, 竹崎 俊一郎, 藤原 圭志

  Japanese Journal of Radiology 42 Suppl. 4 - 4 (公社)日本医学放射線学会 2024年02月
• Utility of Echo Planar Imaging With Compressed Sensing-Sensitivity Encoding (EPICS) for the Evaluation of the Head and Neck Region.

  Yuya Hirano, Noriyuki Fujima, Kinya Ishizaka, Takuya Aoike, Junichi Nakagawa, Masami Yoneyama, Kohsuke Kudo

  Cureus 16 2 e54203  2024年02月 

  Purpose This study aimed to compare the image quality between echo planar imaging (EPI) with compressed sensing-sensitivity encoding (EPICS)-based diffusion-weighted imaging (DWI) and conventional parallel imaging (PI)-based DWI of the head and neck. Materials and methods Ten healthy volunteers participated in this study. EPICS-DWI was acquired based on an axial spin-echo EPI sequence with EPICS acceleration factors of 2, 3, and 4, respectively. Conventional PI-DWI was acquired using the same acceleration factors (i.e., 2, 3, and 4). Quantitative assessment was performed by measuring the signal-to-noise ratio (SNR) and apparent diffusion coefficient (ADC) in a circular region of interest (ROI) on the parotid and submandibular glands. For qualitative evaluation, a three-point visual grading system was used to assess the (1) overall image quality and (2) degree of image distortion. Results In the quantitative assessment, the SNR of the parotid gland in EPICS-DWI was significantly higher than that of PI-DWI in acceleration factors of 3 and 4 (p<0.05). In a comparison of ADC values, significant differences were not observed between EPICS-DWI and PI-DWI. In the qualitative assessment, the overall image quality of EPICS-DWI was significantly higher than that of PI-DWI for acceleration factors 3 and 4 (p<0.05). The degree of image distortion was significantly larger in EPICS-DWI with an acceleration factor of 2 than that of 3 or 4 (p<0.01, respectively). Conclusion Under the appropriate parameter setting, EPICS-DWI demonstrated higher SNR and better overall image quality for head and neck imaging than PI-DWI, without increasing image distortion.
• Diagnosis of skull-base invasion by nasopharyngeal tumors on CT with a deep-learning approach.

  Junichi Nakagawa, Noriyuki Fujima, Kenji Hirata, Taisuke Harada, Naoto Wakabayashi, Yuki Takano, Akihiro Homma, Satoshi Kano, Kazuyuki Minowa, Kohsuke Kudo

  Japanese journal of radiology 2024年01月27日 

  PURPOSE: To develop a convolutional neural network (CNN) model to diagnose skull-base invasion by nasopharyngeal malignancies in CT images and evaluate the model's diagnostic performance. MATERIALS AND METHODS: We divided 100 malignant nasopharyngeal tumor lesions into a training (n = 70) and a test (n = 30) dataset. Two head/neck radiologists reviewed CT and MRI images and determined the positive/negative skull-base invasion status of each case (training dataset: 29 invasion-positive and 41 invasion-negative; test dataset: 13 invasion-positive and 17 invasion-negative). Preprocessing involved extracting continuous slices of the nasopharynx and clivus. The preprocessed training dataset was used for transfer learning with Residual Neural Networks 50 to create a diagnostic CNN model, which was then tested on the preprocessed test dataset to determine the invasion status and model performance. Original CT images from the test dataset were reviewed by a radiologist with extensive head/neck imaging experience (senior reader: SR) and another less-experienced radiologist (junior reader: JR). Gradient-weighted class activation maps (Grad-CAMs) were created to visualize the explainability of the invasion status classification. RESULTS: The CNN model's diagnostic accuracy was 0.973, significantly higher than those of the two radiologists (SR: 0.838; JR: 0.595). Receiver operating characteristic curve analysis gave an area under the curve of 0.953 for the CNN model (versus 0.832 and 0.617 for SR and JR; both p < 0.05). The Grad-CAMs suggested that the invasion-negative cases were present predominantly in bone marrow, while the invasion-positive cases exhibited osteosclerosis and nasopharyngeal masses. CONCLUSIONS: This CNN technique would be useful for CT-based diagnosis of skull-base invasion by nasopharyngeal malignancies.
• Fully automated 3D machine learning model for HPV status characterization in oropharyngeal squamous cell carcinomas based on CT images.

  Edwin Qiu, Maryam Vejdani-Jahromi, Artem Kaliaev, Sherwin Fazelpour, Deniz Goodman, Inseon Ryoo, V Carlota Andreu-Arasa, Noriyuki Fujima, Karen Buch, Osamu Sakai

  American journal of otolaryngology 45 4 104357 - 104357 2024年 

  BACKGROUND: Human papillomavirus (HPV) status plays a major role in predicting oropharyngeal squamous cell carcinoma (OPSCC) survival. This study assesses the accuracy of a fully automated 3D convolutional neural network (CNN) in predicting HPV status using CT images. METHODS: Pretreatment CT images from OPSCC patients were used to train a 3D DenseNet-121 model to predict HPV-p16 status. Performance was evaluated by the ROC Curve (AUC), sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and F1 score. RESULTS: The network achieved a mean AUC of 0.80 ± 0.06. The best-preforming fold had a sensitivity of 0.86 and specificity of 0.92 at the Youden's index. The PPV, NPV, and F1 scores are 0.97, 0.71, and 0.82, respectively. CONCLUSIONS: A fully automated CNN can characterize the HPV status of OPSCC patients with high sensitivity and specificity. Further refinement of this algorithm has the potential to provide a non-invasive tool to guide clinical management.
• Comparing accuracy of machine learning approaches to identifying parathyroid adenomas: Lessons and new directions.

  Cynthia Greene, Noriyuki Fujima, Osamu Sakai, V Carlota Andreu-Arasa

  American journal of otolaryngology 45 2 104155 - 104155 2024年 

  PURPOSE: The purpose of this investigation is to understand the accuracy of machine learning techniques to detect biopsy-proven adenomas from similar appearing lymph nodes and factors that influence accuracy by comparing support vector machine (SVM) and bidirectional Long short-term memory (Bi-LSTM) analyses. This will provide greater insight into how these tools could integrate multidimensional data and aid the detection of parathyroid adenomas consistently and accurately. METHODS: Ninety-nine patients were identified; 93 4D-CTs of patients with pathology-proven parathyroid adenomas were reviewed; 94 parathyroid adenomas and 112 lymph nodes were analyzed. A 2D slice through the lesions in each phase was used to perform sequence classification with ResNet50 as the pre-trained network to construct the Bi-LSTM model, and the mean enhancement curves were used to form an SVM model. The model characteristics and accuracy were calculated for the training and validation data sets. RESULTS: On the training data, the area under the curve (AUC) of the Bi-LSTM was 0.99, while the SVM was 0.95 and statistically significant on the DeLong test. The overall accuracy of the Bi-LSTM on the validation data set was 92 %, while the SVM was 88 %. The accuracy for parathyroid adenomas specifically was 93 % for the Bi-LSTM and 83 % for the SVM model. CONCLUSION: Enhancement characteristics are a distinguishing feature that accurately identifies parathyroid adenomas alone. The Bi-LSTM performs statistically better in identifying parathyroid adenomas than the SVM analysis when using both morphologic and enhancement information to distinguish between parathyroid adenomas and lymph nodes. SUMMARY STATEMENT: The Bi-LSTM more accurately identifies parathyroid adenomas than the SVM analysis, which uses both morphologic and enhancement information to distinguish between parathyroid adenomas and lymph nodes, performs statistically better.
• Revolutionizing radiation therapy: the role of AI in clinical practice.

  Mariko Kawamura, Takeshi Kamomae, Masahiro Yanagawa, Koji Kamagata, Shohei Fujita, Daiju Ueda, Yusuke Matsui, Yasutaka Fushimi, Tomoyuki Fujioka, Taiki Nozaki, Akira Yamada, Kenji Hirata, Rintaro Ito, Noriyuki Fujima, Fuminari Tatsugami, Takeshi Nakaura, Takahiro Tsuboyama, Shinji Naganawa

  Journal of radiation research 65 1 1 - 9 2023年11月22日 

  This review provides an overview of the application of artificial intelligence (AI) in radiation therapy (RT) from a radiation oncologist's perspective. Over the years, advances in diagnostic imaging have significantly improved the efficiency and effectiveness of radiotherapy. The introduction of AI has further optimized the segmentation of tumors and organs at risk, thereby saving considerable time for radiation oncologists. AI has also been utilized in treatment planning and optimization, reducing the planning time from several days to minutes or even seconds. Knowledge-based treatment planning and deep learning techniques have been employed to produce treatment plans comparable to those generated by humans. Additionally, AI has potential applications in quality control and assurance of treatment plans, optimization of image-guided RT and monitoring of mobile tumors during treatment. Prognostic evaluation and prediction using AI have been increasingly explored, with radiomics being a prominent area of research. The future of AI in radiation oncology offers the potential to establish treatment standardization by minimizing inter-observer differences in segmentation and improving dose adequacy evaluation. RT standardization through AI may have global implications, providing world-standard treatment even in resource-limited settings. However, there are challenges in accumulating big data, including patient background information and correlating treatment plans with disease outcomes. Although challenges remain, ongoing research and the integration of AI technology hold promise for further advancements in radiation oncology.
• Improvement of image quality in diffusion-weighted imaging with model-based deep learning reconstruction for evaluations of the head and neck.

  Noriyuki Fujima, Junichi Nakagawa, Hiroyuki Kameda, Yohei Ikebe, Taisuke Harada, Yukie Shimizu, Nayuta Tsushima, Satoshi Kano, Akihiro Homma, Jihun Kwon, Masami Yoneyama, Kohsuke Kudo

  Magma (New York, N.Y.) 2023年11月21日 

  OBJECTIVES: To investigate the utility of deep learning (DL)-based image reconstruction using a model-based approach in head and neck diffusion-weighted imaging (DWI). MATERIALS AND METHODS: We retrospectively analyzed the cases of 41 patients who underwent head/neck DWI. The DWI in 25 patients demonstrated an untreated lesion. We performed qualitative and quantitative assessments in the DWI analyses with both deep learning (DL)- and conventional parallel imaging (PI)-based reconstructions. For the qualitative assessment, we visually evaluated the overall image quality, soft tissue conspicuity, degree of artifact(s), and lesion conspicuity based on a five-point system. In the quantitative assessment, we measured the signal-to-noise ratio (SNR) of the bilateral parotid glands, submandibular gland, the posterior muscle, and the lesion. We then calculated the contrast-to-noise ratio (CNR) between the lesion and the adjacent muscle. RESULTS: Significant differences were observed in the qualitative analysis between the DWI with PI-based and DL-based reconstructions for all of the evaluation items (p < 0.001). In the quantitative analysis, significant differences in the SNR and CNR between the DWI with PI-based and DL-based reconstructions were observed for all of the evaluation items (p = 0.002 ~ p < 0.001). DISCUSSION: DL-based image reconstruction with the model-based technique effectively provided sufficient image quality in head/neck DWI.
• From FDG and beyond: the evolving potential of nuclear medicine.

  Kenji Hirata, Koji Kamagata, Daiju Ueda, Masahiro Yanagawa, Mariko Kawamura, Takeshi Nakaura, Rintaro Ito, Fuminari Tatsugami, Yusuke Matsui, Akira Yamada, Yasutaka Fushimi, Taiki Nozaki, Shohei Fujita, Tomoyuki Fujioka, Takahiro Tsuboyama, Noriyuki Fujima, Shinji Naganawa

  Annals of nuclear medicine 37 11 583 - 595 2023年09月25日 

  The radiopharmaceutical 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) has been dominantly used in positron emission tomography (PET) scans for over 20 years, and due to its vast utility its applications have expanded and are continuing to expand into oncology, neurology, cardiology, and infectious/inflammatory diseases. More recently, the addition of artificial intelligence (AI) has enhanced nuclear medicine diagnosis and imaging with FDG-PET, and new radiopharmaceuticals such as prostate-specific membrane antigen (PSMA) and fibroblast activation protein inhibitor (FAPI) have emerged. Nuclear medicine therapy using agents such as [177Lu]-dotatate surpasses conventional treatments in terms of efficacy and side effects. This article reviews recently established evidence of FDG and non-FDG drugs and anticipates the future trajectory of nuclear medicine.
• Multiparametric machine learning algorithm for human papillomavirus status and survival prediction in oropharyngeal cancer patients.

  Sherwin Fazelpour, Maryam Vejdani-Jahromi, Artem Kaliaev, Edwin Qiu, Deniz Goodman, V Carlota Andreu-Arasa, Noriyuki Fujima, Osamu Sakai

  Head & neck 45 11 2882 - 2892 2023年09月22日 

  BACKGROUND: Human papillomavirus (HPV) status influences prognosis in oropharyngeal cancer (OPC). Identifying high-risk patients are critical to improving treatment. We aim to provide a noninvasive opportunity for managing OPC patients by training multiple machine learning pipelines to determine the best model for characterizing HPV status and survival. METHODS: Multi-parametric algorithms were designed using a 492 OPC patient database. HPV status incorporated age, sex, smoking/drinking habits, cancer subsite, TNM, and AJCC 7th edition staging. Survival considered HPV model inputs plus HPV status. Patients were split 4:1 training: testing. Algorithm efficacy was assessed through accuracy and area under the receiver operator characteristic curve (AUC). RESULTS: From 31 HPV status models, ensemble yielded 0.83 AUC and 78.7% accuracy. From 38 survival models, ensemble yielded 0.91 AUC and 87.7% accuracy. CONCLUSION: Results reinforce artificial intelligence's potential to use tumor imaging and patient characterizations for HPV status and outcome prediction. Utilizing these algorithms can optimize clinical guidance and patient care noninvasively.
• New trend in artificial intelligence-based assistive technology for thoracic imaging.

  Masahiro Yanagawa, Rintaro Ito, Taiki Nozaki, Tomoyuki Fujioka, Akira Yamada, Shohei Fujita, Koji Kamagata, Yasutaka Fushimi, Takahiro Tsuboyama, Yusuke Matsui, Fuminari Tatsugami, Mariko Kawamura, Daiju Ueda, Noriyuki Fujima, Takeshi Nakaura, Kenji Hirata, Shinji Naganawa

  La Radiologia medica 128 10 1236 - 1249 2023年08月28日 

  Although there is no solid agreement for artificial intelligence (AI), it refers to a computer system with intelligence similar to that of humans. Deep learning appeared in 2006, and more than 10 years have passed since the third AI boom was triggered by improvements in computing power, algorithm development, and the use of big data. In recent years, the application and development of AI technology in the medical field have intensified internationally. There is no doubt that AI will be used in clinical practice to assist in diagnostic imaging in the future. In qualitative diagnosis, it is desirable to develop an explainable AI that at least represents the basis of the diagnostic process. However, it must be kept in mind that AI is a physician-assistant system, and the final decision should be made by the physician while understanding the limitations of AI. The aim of this article is to review the application of AI technology in diagnostic imaging from PubMed database while particularly focusing on diagnostic imaging in thorax such as lesion detection and qualitative diagnosis in order to help radiologists and clinicians to become more familiar with AI in thorax.
• Fairness of artificial intelligence in healthcare: review and recommendations.

  Daiju Ueda, Taichi Kakinuma, Shohei Fujita, Koji Kamagata, Yasutaka Fushimi, Rintaro Ito, Yusuke Matsui, Taiki Nozaki, Takeshi Nakaura, Noriyuki Fujima, Fuminari Tatsugami, Masahiro Yanagawa, Kenji Hirata, Akira Yamada, Takahiro Tsuboyama, Mariko Kawamura, Tomoyuki Fujioka, Shinji Naganawa

  Japanese journal of radiology 42 1 3 - 15 2023年08月04日 

  In this review, we address the issue of fairness in the clinical integration of artificial intelligence (AI) in the medical field. As the clinical adoption of deep learning algorithms, a subfield of AI, progresses, concerns have arisen regarding the impact of AI biases and discrimination on patient health. This review aims to provide a comprehensive overview of concerns associated with AI fairness; discuss strategies to mitigate AI biases; and emphasize the need for cooperation among physicians, AI researchers, AI developers, policymakers, and patients to ensure equitable AI integration. First, we define and introduce the concept of fairness in AI applications in healthcare and radiology, emphasizing the benefits and challenges of incorporating AI into clinical practice. Next, we delve into concerns regarding fairness in healthcare, addressing the various causes of biases in AI and potential concerns such as misdiagnosis, unequal access to treatment, and ethical considerations. We then outline strategies for addressing fairness, such as the importance of diverse and representative data and algorithm audits. Additionally, we discuss ethical and legal considerations such as data privacy, responsibility, accountability, transparency, and explainability in AI. Finally, we present the Fairness of Artificial Intelligence Recommendations in healthcare (FAIR) statement to offer best practices. Through these efforts, we aim to provide a foundation for discussing the responsible and equitable implementation and deployment of AI in healthcare.
• Recent advances in artificial intelligence for cardiac CT: Enhancing diagnosis and prognosis prediction.

  Fuminari Tatsugami, Takeshi Nakaura, Masahiro Yanagawa, Shohei Fujita, Koji Kamagata, Rintaro Ito, Mariko Kawamura, Yasutaka Fushimi, Daiju Ueda, Yusuke Matsui, Akira Yamada, Noriyuki Fujima, Tomoyuki Fujioka, Taiki Nozaki, Takahiro Tsuboyama, Kenji Hirata, Shinji Naganawa

  Diagnostic and interventional imaging 2023年07月04日 

  Recent advances in artificial intelligence (AI) for cardiac computed tomography (CT) have shown great potential in enhancing diagnosis and prognosis prediction in patients with cardiovascular disease. Deep learning, a type of machine learning, has revolutionized radiology by enabling automatic feature extraction and learning from large datasets, particularly in image-based applications. Thus, AI-driven techniques have enabled a faster analysis of cardiac CT examinations than when they are analyzed by humans, while maintaining reproducibility. However, further research and validation are required to fully assess the diagnostic performance, radiation dose-reduction capabilities, and clinical correctness of these AI-driven techniques in cardiac CT. This review article presents recent advances of AI in the field of cardiac CT, including deep-learning-based image reconstruction, coronary artery motion correction, automatic calcium scoring, automatic epicardial fat measurement, coronary artery stenosis diagnosis, fractional flow reserve prediction, and prognosis prediction, analyzes current limitations of these techniques and discusses future challenges.
• Clinical applications of artificial intelligence in liver imaging.

  Akira Yamada, Koji Kamagata, Kenji Hirata, Rintaro Ito, Takeshi Nakaura, Daiju Ueda, Shohei Fujita, Yasutaka Fushimi, Noriyuki Fujima, Yusuke Matsui, Fuminari Tatsugami, Taiki Nozaki, Tomoyuki Fujioka, Masahiro Yanagawa, Takahiro Tsuboyama, Mariko Kawamura, Shinji Naganawa

  La Radiologia medica 128 6 655 - 667 2023年05月10日 

  This review outlines the current status and challenges of the clinical applications of artificial intelligence in liver imaging using computed tomography or magnetic resonance imaging based on a topic analysis of PubMed search results using latent Dirichlet allocation. LDA revealed that "segmentation," "hepatocellular carcinoma and radiomics," "metastasis," "fibrosis," and "reconstruction" were current main topic keywords. Automatic liver segmentation technology using deep learning is beginning to assume new clinical significance as part of whole-body composition analysis. It has also been applied to the screening of large populations and the acquisition of training data for machine learning models and has resulted in the development of imaging biomarkers that have a significant impact on important clinical issues, such as the estimation of liver fibrosis, recurrence, and prognosis of malignant tumors. Deep learning reconstruction is expanding as a new technological clinical application of artificial intelligence and has shown results in reducing contrast and radiation doses. However, there is much missing evidence, such as external validation of machine learning models and the evaluation of the diagnostic performance of specific diseases using deep learning reconstruction, suggesting that the clinical application of these technologies is still in development.
• Clinical utility of single-shot echo-planar diffusion-weighted imaging using L1-regularized iterative sensitivity encoding in prostate MRI.

  Noriko Nishioka, Noriyuki Fujima, Satonori Tsuneta, Masami Yoneyama, Ryuji Matsumoto, Takashige Abe, Rina Kimura, Keita Sakamoto, Fumi Kato, Kohsuke Kudo

  Medicine 102 17 e33639  2023年04月25日 

  We investigated the ability of echo-planar imaging with L1-regularized iterative sensitivity encoding-based diffusion-weighted imaging (DWI) to improve the image quality and reduce the scanning time in prostate magnetic resonance imaging. We retrospectively analyzed 109 cases of prostate magnetic resonance imaging. We compared variables in the quantitative and qualitative assessments among 3 imaging groups: conventional parallel imaging-based DWI (PI-DWI) with an acquisition time of 3 minutes 15 seconds; echo-planar imaging with L1-regularized iterative sensitivity encoding-based DWI (L1-DWI) with a normal acquisition time (L1-DWINEX12) of 3 minutes 15 seconds; and L1-DWI with a half acquisition time (L1-DWINEX6) of 1 minute 45 seconds. As a quantitative assessment, the signal-to-noise ratio (SNR) of DWI (SNR-DWI), the contrast-to-noise ratio (CNR) of DWI (CNR-DWI), and the CNR of apparent diffusion coefficient were measured. As a qualitative assessment, the image quality and visual detectability of prostate carcinoma were evaluated. In the quantitative analysis, L1-DWINEX12 showed significantly higher SNR-DWI than PI-DWI (P = .0058) and L1-DWINEX6 (P < .0001). In the qualitative analysis, the image quality score for L1-DWINEX12 was significantly higher than those of PI-DWI and L1-DWINEX6. A non-inferiority assessment demonstrated that L1-DWINEX6 was non-inferior to PI-DWI in terms of both quantitative CNR-DWI and qualitative grading of image quality with a <20% inferior margin. L1-DWI successfully demonstrated a reduced scanning time while maintaining good image quality.
• Chronological Volume Changes of the Temporal Muscle Pedicle Used for Encephalo-myo-synangiosis in Combined Revascularization for Moyamoya Disease: A Prospective Observational Study.

  Makoto Mizushima, Masaki Ito, Noriyuki Fujima, Haruto Uchino, Taku Sugiyama, Miki Fujimura

  Neurologia medico-chirurgica 63 7 304 - 312 2023年04月20日 

  Although postoperative neurological events due to brain compression by the swollen temporal muscle are a rare complication, the chronological volume changes of the temporal muscle pedicle and their clinical impact have not yet been documented. This prospective observational study aimed to investigate the chronological volume changes in the temporal muscle pedicle in Moyamoya disease (MMD). Eighteen consecutive combined revascularization procedures using the temporal muscle were performed for symptomatic MMD in 2021. The postoperative pedicle volume was quantified using repeated computed tomography images on postoperative days (PODs) 0, 1, 7, 14, and 30. Postoperative neurological events with radiological evaluations and collateral development evaluated using magnetic resonance angiography obtained 6 months after surgery were studied. On average, the postoperative temporal muscle pedicle volume was most significantly increased by as much as 112% ± 9.6% on POD 7 (P < 0.001) and decreased by as little as 52% ± 21% on POD 30 (P < 0.0001) relative to POD 0. One exceptional patient (overall incidence, 5.6%) demonstrated postoperative transient neurological events due to brain compression by the swollen temporal muscle with decreased focal cerebral blood flow in the adjacent cortical area. The postoperative collateral development via direct and indirect revascularizations was confirmed in 16 (89%) and 12 (67%) hemispheres, respectively. All patients, except for one rebleeding case, showed independent outcomes at the mean latest follow-up period on 290 ± 96 days after surgery. Our observations confirmed the temporal profile of muscle pedicle volume changes after combined revascularization. Through routine attempts to avoid the unfavorable effects of temporal muscle swelling, combined revascularization can provide favorable outcomes in symptomatic MMD.
• Non-Gaussian model-based diffusion-weighted imaging of oral squamous cell carcinoma: associations with Ki-67 proliferation status.

  Tomoka Shima, Noriyuki Fujima, Shigeru Yamano, Hiroyuki Kameda, Masaaki Suzuka, Akiko Takeuchi, Yurika Kinoshita, Nanami Iwai, Kohsuke Kudo, Kazuyuki Minowa

  Oral radiology 39 4 661 - 667 2023年03月27日 

  OBJECTIVES: To investigate possible associations between diffusion-weighted imaging (DWI) parameters derived from a non-Gaussian model fitting and Ki-67 status in patients with oral squamous cell carcinoma (OSCC). METHODS: Twenty-four patients with newly diagnosed OSCC were prospectively recruited. DWI was performed using six b-values (0-2500). The diffusion-related parameters of kurtosis value (K), kurtosis-corrected diffusion coefficient (DK), diffusion heterogeneity (α), distributed diffusion coefficient (DDC), slow diffusion coefficient (Dslow), and apparent diffusion coefficient (ADC) were calculated from four diffusion fitting models. Ki-67 status was categorized as low (Ki-67 percentage score < 20%), middle (20-50%), or high (> 50%). Kruskal-Wallis tests were performed between each non-Gaussian diffusion model parameters and Ki-67 grade. RESULTS: The Kruskal-Wallis tests revealed that multiple parameters (K, ADC, Dk, DDC and Dslow) showed statistically significant differences between the three levels of Ki-67 status (K: p = 0.020, ADC: p = 0.012, Dk: p = 0.027, DDC: p = 0.007 and Dslow: p = 0.026). CONCLUSIONS: Several non-Gaussian diffusion model parameters and ADC values were significantly associated with Ki-67 status and have potential as promising prognostic biomarkers in patients with OSCC.
• Mechanical Properties of 3D-Printed Transparent Flexible Resin Used for Vascular Model Simulation Compared with Porcine Arteries.

  Ryo Morita, Takayuki Nonoyama, Daisuke Abo, Takeshi Soyama, Fujima Noriyuki, Tetsuaki Imai, Hiroyuki Hamaguchi, Takuto Kameda, Osamu Sugita, Bunya Takahashi, Naoya Kinota, Kohsuke Kudo

  Journal of vascular and interventional radiology : JVIR 34 5 871 - 878 2023年01月13日 [査読有り]
   

  PURPOSE: To develop a vascular intervention simulation model that replicates the characteristics of a human patient, the mechanical properties of a three-dimensional (3D)- printed transparent flexible resin were compared with those of porcine arteries using the elastic modulus (E) and kinetic friction coefficient (μ_k). MATERIALS AND METHODS: Resin plates were created from transparent flexible resin using a 3D printer. Porcine artery plates were prepared by excising the aorta. E, adhesive strength of resin and arterial surface toward polyethylene plate, was measured with a tensile-compressive mechanical tester. The resin transparency was measured with an ultraviolet-visible light spectrometer. μ_k of the resin plate surface after applying silicone spray for 1-5 s and that of the artery were measured with a translational friction tester. RESULTS: E differed significantly between the arteries and resin plates at each curing time (0.20 ±0.04 vs. 8.53 ±2.37 MPa for a curing time of 1 min, P<0.05). The resin was stiffer than the arteries, regardless of the curing times. The visible light transmittance and adhesive strength of the resin decreased as the curing time increased. The adhesive strength of the artery was the lowest. μ_k of the silicone-coated resin surface created by applying silicone for 2-3 s (thickness of the silicone layer: 1.6-2 μm) was comparable with that of the artery, indicating that the coating imparted a similar slippage to the resin as the living artery. CONCLUSION: Transparent flexible resin is useful for creating a transparent and slippery vascular model for vascular intervention simulation.
• MR vessel-encoded arterial spin labeling with the placement of metallic items to visualize the territorial blood flow after extracranial-intracranial bypass surgery: a proof-of-concept study.

  Tetsuji Hayashi, Noriyuki Fujima, Taisuke Harada, Akiyoshi Hamaguchi, Shuichi Kodera

  Acta radiologica (Stockholm, Sweden : 1987) 64 5 2841851221151144 - 2841851221151144 2023年01月12日 

  BACKGROUND: Depiction of bypass blood flow in patients who received extracranial-intracranial (EC-IC) bypass surgery is important for patient care. PURPOSE: To develop a vessel-encoded arterial spin labeling (VE-ASL) method using surgical staples as a magnetic resonance (MR)-conditional product in patients who received EC-IC bypass surgery. MATERIAL AND METHODS: Pseudo-continuous labeling was used for VE-ASL acquisition with a 3-T MR unit. First, an experimental study was conducted to determine the appropriate number of surgical staples to obtain a spatially sufficient saturation effect. Thereafter, four healthy normal volunteers underwent a VE-ASL study to confirm the sufficiency of the saturation effect to the right or left common carotid artery. Finally, VE-ASL scanning was performed in seven patients after EC-IC bypass surgery to confirm the ability of VE-ASL to visualize the territorial bypass perfusion. All qualitative evaluation was performed by two neuroradiologists using a 3-point grading system (2 = good, 1 = moderate, 0 = poor). RESULTS: A quantity of 200 staples was found to be appropriate for VE-ASL scanning. In healthy volunteers, one neuroradiologist rated the images of all four cases as good, while the other rated three cases as good and one case as moderate. For the seven patients after EC-IC bypass surgery, one neuroradiologist rated all seven cases as good, and the other rated six cases as good and one case as moderate. CONCLUSION: VE-ASL using surgical staples might be useful for the evaluation of territorial bypass perfusion in patients after EC-IC bypass surgery.
• Current State of Artificial Intelligence in Clinical Applications for Head and Neck MR Imaging

  Noriyuki Fujima, Koji Kamagata, Daiju Ueda, Shohei Fujita, Yasutaka Fushimi, Masahiro Yanagawa, Rintaro Ito, Takahiro Tsuboyama, Mariko Kawamura, Takeshi Nakaura, Akira Yamada, Taiki Nozaki, Tomoyuki Fujioka, Yusuke Matsui, Kenji Hirata, Fuminari Tatsugami, Shinji Naganawa

  Magnetic Resonance in Medical Sciences 22 4 401 - 414 2023年 

  Due primarily to the excellent soft tissue contrast depictions provided by MRI, the widespread application of head and neck MRI in clinical practice serves to assess various diseases. Artificial intelligence (AI)-based methodologies, particularly deep learning analyses using convolutional neural networks, have recently gained global recognition and have been extensively investigated in clinical research for their applicability across a range of categories within medical imaging, including head and neck MRI. Analytical approaches using AI have shown potential for addressing the clinical limitations associated with head and neck MRI. In this review, we focus primarily on the technical advancements in deep-learning-based methodologies and their clinical utility within the field of head and neck MRI, encompassing aspects such as image acquisition and reconstruction, lesion segmentation, disease classification and diagnosis, and prognostic prediction for patients presenting with head and neck diseases. We then discuss the limitations of current deep-learning-based approaches and offer insights regarding future challenges in this field.
• Comparison of Access Route for Endovascular Treatment by Time-Spatial Labeling Inversion Pulse (Time-SLIP) MRA and Contrast-Enhanced MRA

  Satoshi Kobayashi, Toshiya Osanai, Taku Sugiyama, Noriyuki Fujima, Ryo Takagi, Isao Yokota, Akiyoshi Hamaguchi, Toshitaka Nakamura, Kazutoshi Hida, Miki Fujimura

  Journal of Neuroendovascular Therapy 17 6 120 - 124 2023年 

  OBJECTIVE: In endovascular treatment, it is important to evaluate the access route for placing a catheter into the common carotid artery (CCA) promptly and safely prior to the procedure. We examined whether non-contrast MRA using time-spatial labeling inversion pulse (Time-SLIP) can be used in patients prior to endovascular thrombectomy for acute ischemic stroke. We compared Time-SLIP MRA to contrast-enhanced (CE) MRA and evaluated the efficacy in the evaluation of access routes. METHODS: We retrospectively reviewed 31 patients admitted between October 2018 and December 2018 for cerebral infarction at our hospital. Blood vessels were imaged from the aortic arch to the CCA. A radiologist blindly evaluated quality score, stenosis, shape of the aorta, and degree of tortuosity. RESULTS: There were no "non-diagnostic" images. The sensitivity, specificity, positive predictive value, and negative predictive value for stenosis were 83%, 96%, 83%, and 96%, respectively. The sensitivity for the aorta type classification was 100%. The sensitivity for mild tortuosity was 93%, for moderate was 100%, and for severe was 100%. CONCLUSION: Time-SLIP MRA can be an alternative to CE MRA in access route assessment for patients with cerebral infarction who are not eligible for acute thrombectomy therapy.
• Utility of the deep learning technique for the diagnosis of orbital invasion on CT in patients with a nasal or sinonasal tumor.

  Junichi Nakagawa, Noriyuki Fujima, Kenji Hirata, Minghui Tang, Satonori Tsuneta, Jun Suzuki, Taisuke Harada, Yohei Ikebe, Akihiro Homma, Satoshi Kano, Kazuyuki Minowa, Kohsuke Kudo

  Cancer imaging : the official publication of the International Cancer Imaging Society 22 1 52 - 52 2022年09月22日 

  BACKGROUND: In nasal or sinonasal tumors, orbital invasion beyond periorbita by the tumor is one of the important criteria in the selection of the surgical procedure. We investigated the usefulness of the convolutional neural network (CNN)-based deep learning technique for the diagnosis of orbital invasion, using computed tomography (CT) images. METHODS: A total of 168 lesions with malignant nasal or sinonasal tumors were divided into a training dataset (n = 119) and a test dataset (n = 49). The final diagnosis (invasion-positive or -negative) was determined by experienced radiologists who carefully reviewed all of the CT images. In a CNN-based deep learning analysis, a slice of the square target region that included the orbital bone wall was extracted and fed into a deep-learning training session to create a diagnostic model using transfer learning with the Visual Geometry Group 16 (VGG16) model. The test dataset was subsequently tested in CNN-based diagnostic models and by two other radiologists who were not specialized in head and neck radiology. At approx. 2 months after the first reading session, two radiologists again reviewed all of the images in the test dataset, referring to the diagnoses provided by the trained CNN-based diagnostic model. RESULTS: The diagnostic accuracy was 0.92 by the CNN-based diagnostic models, whereas the diagnostic accuracies by the two radiologists at the first reading session were 0.49 and 0.45, respectively. In the second reading session by two radiologists (diagnosing with the assistance by the CNN-based diagnostic model), marked elevations of the diagnostic accuracy were observed (0.94 and 1.00, respectively). CONCLUSION: The CNN-based deep learning technique can be a useful support tool in assessing the presence of orbital invasion on CT images, especially for non-specialized radiologists.
• Long-term consequences of residual lesions after chemoradiotherapy in patients with germinoma at onset.

  Shigeru Yamaguchi, Michinari Okamoto, Yukitomo Ishi, Ryosuke Sawaya, Hiroaki Motegi, Minako Sugiyama, Taisuke Harada, Noriyuki Fujima, Takashi Mori, Takayuki Hashimoto, Emi Takakuwa, Atsushi Manabe, Kohsuke Kudo, Hidefumi Aoyama, Miki Fujimura

  Journal of neurosurgery. Pediatrics 1 - 8 2022年09月09日 

  OBJECTIVE: In patients with intracranial germ cell tumors, residual lesions are sometimes observed after completion of primary chemoradiotherapy. Although salvage resection of these end-of-treatment residual lesions is recommended for patients with nongerminomatous germ cell tumors, the necessity of early salvage resection for those with germinoma is not clear. The aim of this study was to investigate the frequency of residual germinoma lesions after primary chemoradiotherapy, as well as their management, long-term consequences, and prognosis. METHODS: The authors retrospectively reviewed patients who were primarily treated for germinoma between 2002 and 2021. Residual lesions were evaluated with MRI with and without contrast enhancement within 2 weeks after chemoradiotherapy. The decision to perform salvage resection of residual lesions was at the discretion of the treating physicians. The change in appearance of residual lesions was assessed with serial MRI. Overall survival (OS), progression-free survival (PFS), and recurrence pattern were also investigated. RESULTS: Sixty-nine patients were treated with chemoradiotherapy for germinoma, with a mean follow-up period of 108 months. Residual lesions were radiologically observed in 30 patients (43.5%). Among these, 5 patients (3 with pineal lesions and 2 with basal ganglia lesions) underwent salvage resection. Pathological examination revealed teratomatous components in 3 patients, whereas no tumoral components were identified in 2 patients. One patient with a basal ganglia lesion showed worsening of hemiparesis postoperatively. The remaining 25 patients received watchful observation without surgical intervention. Chronological periodic radiological change in residual lesions was evaluated in 21 patients. One year after primary treatment, the size of the residual lesions was stable and had decreased in 10 and 11 patients, respectively. None of the lesions increased in size. The 10-year PFS and OS rates were 96.7% and 97.3% in patients without residual lesions (n = 39), and 87.1% and 100% in patients with residual lesions (n = 30), respectively. Presence of residual lesions had no significant effect on PFS or OS. All recurrences occurred at distant sites or via dissemination without progression of the primary tumor site, regardless of the presence of residual lesion. CONCLUSIONS: End-of-treatment residual lesions are not rare in patients with germinoma, and these residual lesions seldom show progression. Because of the potential risk of surgical complications, the indication for early salvage surgery for residual lesions should be carefully determined. Watchful observation is recommended for the majority of these cases.
• The utility of diffusion-weighted T2 mapping for the prediction of histological tumor grade in patients with head and neck squamous cell carcinoma.

  Noriyuki Fujima, Yukie Shimizu, Masami Yoneyama, Junichi Nakagawa, Hiroyuki Kameda, Taisuke Harada, Seijiro Hamada, Takayoshi Suzuki, Nayuta Tsushima, Satoshi Kano, Akihiro Homma, Kohsuke Kudo

  Quantitative imaging in medicine and surgery 12 8 4024 - 4032 2022年08月 

  Background: In head and neck cancers, histopathological information is important for the determination of the tumor characteristics and for predicting the prognosis. The aim of this study was to assess the utility of diffusion-weighted T2 (DW-T2) mapping for the evaluation of tumor histological grade in patients with head and neck squamous cell carcinoma (SCC). Methods: The cases of 41 patients with head and neck SCC (21 well/moderately and 17 poorly differentiated SCC) were retrospectively analyzed. All patients received MR scanning using a 3-Tesla MR unit. The conventional T2 value, DW-T2 value, ratio of DW-T2 value to conventional T2 value, and apparent diffusion coefficient (ADC) were calculated using signal information from the DW-T2 mapping sequence with a manually placed region of interest (ROI). Results: ADC values in the poorly differentiated SCC group were significantly lower than those in the moderately/well differentiated SCC group (P<0.05). The ratio of DW-T2 value to conventional T2 value was also significantly different between poorly and moderately/well differentiated SCC groups (P<0.01). Receiver operating characteristic (ROC) curve analysis of ADC values showed a sensitivity of 0.76, specificity of 0.67, positive predictive value (PPV) of 0.62, negative predictive value (NPV) of 0.8, accuracy of 0.71 and area under the curve (AUC) of 0.73, whereas the ROC curve analysis of the ratio of DW-T2 value to conventional T2 value showed a sensitivity of 0.76, specificity of 0.83, PPV of 0.76, NPV of 0.83, accuracy of 0.8 and AUC of 0.82. Conclusions: DW-T2 mapping might be useful as supportive information for the determination of tumor histological grade in patients with head and neck SCC.
• Amide proton transfer imaging for the determination of human papillomavirus status in patients with oropharyngeal squamous cell carcinoma.

  Noriyuki Fujima, Yukie Shimizu, Masami Yoneyama, Junichi Nakagawa, Hiroyuki Kameda, Taisuke Harada, Seijiro Hamada, Takayoshi Suzuki, Nayuta Tsushima, Satoshi Kano, Akihiro Homma, Kohsuke Kudo

  Medicine 101 28 e29457  2022年07月15日 

  The aim of this study was to investigate the utility of amide proton transfer (APT) imaging for the determination of human papillomavirus (HPV) status in patients with oropharyngeal squamous cell carcinoma (SCC). Thirty-one patients with oropharyngeal SCC were retrospectively evaluated. All patients underwent amide proton transfer imaging using a 3T magnetic resonance (MR) unit. Patients were divided into HPV-positive and -negative groups depending on the pathological findings in their primary tumor. In APT imaging, the primary tumor was delineated with a polygonal region of interest (ROI). Signal information in the ROI was used to calculate the mean, standard deviation (SD) and coefficient of variant (CV) of the APT signals (APT mean, APT SD, and APT CV, respectively). The value of APT CV in the HPV-positive group (0.43 ± 0.04) was significantly lower than that in the HPV-negative group (0.48 ± 0.04) (P = .01). There was no significant difference in APT mean (P = .82) or APT SD (P = .13) between the HPV-positive and -negative groups. Receiver operating characteristic (ROC) curve analysis of APT CV had a sensitivity of 0.75, specificity of 0.8, positive predictive value of 0.75, negative predictive value of 0.8, accuracy of 0.77 and area under the curve (AUC) of 0.8. The APT signal in the HPV-negative group was considered heterogeneous compared to the HPV-positive group. This information might be useful for the determination of HPV status in patients with oropharyngeal SCC.
• Quantitative Susceptibility Mapping: Basic Methods and Clinical Applications.

  Taisuke Harada, Kohsuke Kudo, Noriyuki Fujima, Masato Yoshikawa, Yohei Ikebe, Ryota Sato, Toru Shirai, Yoshitaka Bito, Ikuko Uwano, Mari Miyata

  Radiographics : a review publication of the Radiological Society of North America, Inc 42 4 210054 - 210054 2022年05月06日 

  Quantitative susceptibility mapping (QSM), one of the advanced MRI techniques for evaluating magnetic susceptibility, offers precise quantitative measurements of spatial distributions of magnetic susceptibility. Magnetic susceptibility describes the magnetizability of a material to an applied magnetic field and is a substance-specific value. Recently, QSM has been widely used to estimate various levels of substances in the brain, including iron, hemosiderin, and deoxyhemoglobin (paramagnetism), as well as calcification (diamagnetism). By visualizing iron distribution in the brain, it is possible to identify anatomic structures that are not evident on conventional images and to evaluate various neurodegenerative diseases. It has been challenging to apply QSM in areas outside the brain because of motion artifacts from respiration and heartbeats, as well as the presence of fat, which has a different frequency to the proton. In this review, the authors provide a brief overview of the theoretical background and analyze methods of converting MRI phase images to QSM. Moreover, we provide an overview of the current clinical applications of QSM. Online supplemental material is available for this article. ©RSNA, 2022.
• Phase I Randomized Trial of 17 O-Labeled Water: Safety and Feasibility Study of Indirect Proton MRI for the Evaluation of Cerebral Water Dynamics.

  Taisuke Harada, Kohsuke Kudo, Hiroyuki Kameda, Ryota Sato, Toru Shirai, Yoshitaka Bito, Noriyuki Fujima, Satonori Tsuneta, Toshifumi Nogawa, Kenichiro Maeda, Hiroshi Hayashi, Makoto Sasaki

  Journal of magnetic resonance imaging : JMRI 56 6 1874 - 1882 2022年04月30日 

  BACKGROUND: 17 O-labeled water (PSO17) is a contrast agent developed to measure brain water dynamics and cerebral blood flow. PURPOSE: To evaluate the safety and feasibility of PSO17. STUDY TYPE: Prospective study. SUBJECTS: A total of 12 male healthy volunteers (23.1 ± 1.9 years) were assigned to three groups of four subjects: placebo (normal saline), PSO17 10%, and PSO17 20%. FIELD STRENGTH/SEQUENCE: Dynamic 3D fluid attenuated inversion recovery (FLAIR, fast spin echo with variable refocusing flip angle) scans of the brain were performed with 3-T MRI. ASSESSMENT: Contrast agents were injected 5 minutes after the start of a 10-minute scan. Any symptoms, vital signs, and blood and urine tests were evaluated at five timepoints from preinjection to 4 days after. Blood samples for pharmacokinetic analysis, including half-life (T1/2), maximum fraction (Cmax ), time-to-maximum fraction (Tmax ), and area under the curve (AUC), were collected at 13 timepoints from preinjection to 168 hours after. Regions of interest were set in the cerebral cortex (CC), basal ganglia/thalamus (BG/TM), and white matter (WM), and 17 O concentrations were calculated from signal changes and evaluated using Cmax . STATISTICAL TESTS: All items were compared among the three groups using Tukey-Kramer's honestly significant difference test. Statistical significance was defined as P < 0.5. RESULTS: No safety issues were noted with the intravenous administration of PSO17. The T1/2 was approximately 160 hours, and the AUCs were 1.77 ± 0.10 and 3.75 ± 0.36 in the PSO17 10% and 20% groups, respectively. 17 O fractions calculated from MRI signals were higher in the PSO17 20% group than in the 10% and placebo groups. Significant differences were noted between all pairs of groups in the CC and BG/TM, and between PSO17 20% and both placebo and 10% groups in the WM. DATA CONCLUSION: PSO17 might be considered safe as a contrast medium. Dynamic 3D-FLAIR might detect dose-dependent signal changes and estimate 17 O. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 1.
• Amorphous cellulose nanofiber supercapacitors with voltage-charging performance.

  Mikio Fukuhara, Tomonori Yokotsuka, Toshiyuki Hashida, Tamon Miwa, Nobuhisa Fujima, Masahiro Morita, Takeshi Nakatani, Fuminari Nonomura

  Scientific reports 12 1 5619 - 5619 2022年04月04日 

  The electric charge storage properties of amorphous cellulose nanofiber (ACF) supercapacitors with different metal carboxylate radicals (COOM; M: Na(I), Ca(II), Al(III)) was investigated in terms of charging/discharging behaviours, alternating current impedance analysis, and plane-wave-based first-principles density functional calculations. Na-ACF exhibited a higher storage effect than Ca- and Al-ACFs. The charge storage mechanism for an Na-ACF supercapacitor was proposed using an electric double layer model in a C12H17O11Na electrolyte with an electrical resistivity of 6.8 × 103 Ω cm, based on the migration of protonic soliton. The supercapacitor, which demonstrated fast charging upon voltage application, could illuminate a white LED for 7 s after charging with 10 mA at 18.5 V.
• Artificial intelligence for nuclear medicine in oncology.

  Kenji Hirata, Hiroyuki Sugimori, Noriyuki Fujima, Takuya Toyonaga, Kohsuke Kudo

  Annals of nuclear medicine 36 2 123 - 132 2022年02月 

  As in all other medical fields, artificial intelligence (AI) is increasingly being used in nuclear medicine for oncology. There are many articles that discuss AI from the viewpoint of nuclear medicine, but few focus on nuclear medicine from the viewpoint of AI. Nuclear medicine images are characterized by their low spatial resolution and high quantitativeness. It is noted that AI has been used since before the emergence of deep learning. AI can be divided into three categories by its purpose: (1) assisted interpretation, i.e., computer-aided detection (CADe) or computer-aided diagnosis (CADx). (2) Additional insight, i.e., AI provides information beyond the radiologist's eye, such as predicting genes and prognosis from images. It is also related to the field called radiomics/radiogenomics. (3) Augmented image, i.e., image generation tasks. To apply AI to practical use, harmonization between facilities and the possibility of black box explanations need to be resolved.
• Efficacy of the MRA-Based Road Mapping of the Para-Aortic Access Route before Mechanical Thrombectomy in Patients with Acute Ischemic Stroke.

  Satoshi Kobayashi, Toshiya Osanai, Noriyuki Fujima, Akiyoshi Hamaguchi, Taku Sugiyama, Toshitaka Nakamura, Kazutoshi Hida, Miki Fujimura

  Cerebrovascular diseases extra 12 1 47 - 52 2022年 

  INTRODUCTION: The aim of this study was to clarify whether magnetic resonance angiography (MRA)-based road mapping of the para-aortic transfemoral access route can reduce the procedural time of mechanical thrombectomy in patients with acute ischemic stroke. We further investigated the role of pre-procedural MRA-based road mapping in optimal initial catheter selection for rapid mechanical thrombectomy. MATERIALS AND METHODS: We retrospectively reviewed 57 consecutive patients with acute ischemic stroke who underwent mechanical thrombectomy at our hospital between April 2018 and May 2021. Twenty-nine patients underwent MRA-based road mapping to visualize the para-aortic access route, whereas 28 patients only underwent routine head magnetic resonance imaging/angiography without MRA-based road mapping before neuro-interventional procedures. We then compared the basic procedural times required for mechanical thrombectomy, such as the time from femoral artery puncture to recanalization ("puncture to recanalization time") and the time from the admission to recanalization ("door to recanalization time"), between the groups. RESULTS: MRA-based road mapping significantly reduced the "puncture to recanalization time" (52.0 min vs. 70.0 min; p = 0.019) and the "door to recanalization time" (146 min vs. 183 min; p = 0.013). CONCLUSION: MRA-based road mapping of the para-aortic access route is useful to reduce the procedural time of mechanical thrombectomy in acute stroke patients, possibly by enabling optimal initial catheter selection during the procedure.
• Development of three-dimensional MR neurography using an optimized combination of compressed sensing and parallel imaging.

  Takuya Aoike, Noriyuki Fujima, Masami Yoneyama, Taro Fujiwara, Sayaka Takamori, Suzuko Aoike, Kinya Ishizaka, Kohsuke Kudo

  Magnetic resonance imaging 87 32 - 37 2021年12月27日 

  PURPOSE: To assess the cervical magnetic resonance neurography (MRN) imaging quality obtained with compressed sensing and sensitivity-encoding (compressed SENSE; CS-SENSE) technique in comparison to that obtained with the conventional parallel imaging (i.e., SENSE) technique. MATERIALS AND METHODS: Five healthy volunteers underwent a three-dimensional (3D) turbo spin-echo (TSE)-based cervical MRN examination using a 3.0 Tesla MR-unit. All MRN acquisitions were performed with CS-SENSE and conventional SENSE. We used four acceleration factors (4, 8, 16 and 32) in CS-SENSE. The image quality in MRN was evaluated by assessing the degree of cervical nerve depiction using the contrast ratio (CR) and contrast-noise ratio (CNR) between the cervical nerve and the background signal intensity and a visual scoring system (1: poor, 2: moderate, 3: good). In all of the CR, CNR and visual score, we calculated the ratio of the CS-SENSE-based MRN to that from SENSE-based MRN plus the 95% confidence intervals (CIs) of these ratios. RESULTS: In the multiple comparison of MRN images with the control of conventional SENSE-based MRN, both the quantitative CR values and the visual score for the CS-SENSE factors of 16 and 32 were significantly lower, whereas the CS-SENSE factors of 4 and 8 showed a non-significant difference. In addition, the quantitative CNR values obtained with the CS-SENSE factors of 4 and 8 were significantly higher than that obtained with the conventional SENSE-based MRN while the CS-SENSE factor of 32 was significantly lower, in contrast, the CS-SENSE factors of 16 showed a non-significant difference. For CS-SENSE factors of 4 and 8, all ratios of the CS-SENSE-based MRN values for CR, CNR and visual scores to those from SENSE-based MRN were above 0.95. CONCLUSION: CS-SENSE-based MRN can accomplish fast scanning with sufficient image quality when using a high acceleration factor.
• First-Principle Study on p-n Control of PEDOT-Based Thermoelectric Materials by PTSA Doping.

  Hideki Arimatsu, Yuki Osada, Ryo Takagi, Takuya Fujima

  Polymers 13 20 2021年10月13日 

  Tos, a PSS-free PEDOT-based material, is a promising possible organic thermoelectric material for a practical conversion module because the material reportedly has a large power factor. However, since PEDOT:Tos is mainly reported to be a p-type thermoelectric material, the development of PSS-free PEDOT with n-type thermoelectric properties is desirable. Thus, in order to search for PSS-free PEDOT with n-type thermoelectric properties, we investigated the doping concentration of PTSA dependence of the thermoelectric property using the first-principle calculation. The band structure and the density of state indicated that the n-type thermal electromotive force was attributed to the electrons' large effective mass. Such electrons were produced thanks to the binding of the dopant PTSA to the benzene ring. The contribution of the electron to the Seebeck coefficient increased with increasing PTSA doping concentrations.
• Prediction of the local treatment outcome in patients with oropharyngeal squamous cell carcinoma using deep learning analysis of pretreatment FDG-PET images.

  Noriyuki Fujima, V Carlota Andreu-Arasa, Sara K Meibom, Gustavo A Mercier, Minh Tam Truong, Kenji Hirata, Koichi Yasuda, Satoshi Kano, Akihiro Homma, Kohsuke Kudo, Osamu Sakai

  BMC cancer 21 1 900 - 900 2021年08月06日 

  BACKGROUND: This study aimed to assess the utility of deep learning analysis using pretreatment FDG-PET images to predict local treatment outcome in oropharyngeal squamous cell carcinoma (OPSCC) patients. METHODS: One hundred fifty-four OPSCC patients who received pretreatment FDG-PET were included and divided into training (n = 102) and test (n = 52) sets. The diagnosis of local failure and local progression-free survival (PFS) rates were obtained from patient medical records. In deep learning analyses, axial and coronal images were assessed by three different architectures (AlexNet, GoogLeNET, and ResNet). In the training set, FDG-PET images were analyzed after the data augmentation process for the diagnostic model creation. A multivariate clinical model was also created using a binomial logistic regression model from a patient's clinical characteristics. The test data set was subsequently analyzed for confirmation of diagnostic accuracy. Assessment of local PFS rates was also performed. RESULTS: Training sessions were successfully performed with an accuracy of 74-89%. ROC curve analyses revealed an AUC of 0.61-0.85 by the deep learning model in the test set, whereas it was 0.62 by T-stage, 0.59 by clinical stage, and 0.74 by a multivariate clinical model. The highest AUC (0.85) was obtained with deep learning analysis of ResNet architecture. Cox proportional hazards regression analysis revealed deep learning-based classification by a multivariate clinical model (P < .05), and ResNet (P < .001) was a significant predictor of the treatment outcome. In the Kaplan-Meier analysis, the deep learning-based classification divided the patient's local PFS rate better than the T-stage, clinical stage, and a multivariate clinical model. CONCLUSIONS: Deep learning-based diagnostic model with FDG-PET images indicated its possibility to predict local treatment outcomes in OPSCCs.
• Prediction of the treatment outcome using machine learning with FDG-PET image-based multiparametric approach in patients with oral cavity squamous cell carcinoma.

  N Fujima, V C Andreu-Arasa, S K Meibom, G A Mercier, A R Salama, M T Truong, O Sakai

  Clinical radiology 76 9 711.e1-711.e7  2021年04月29日 

  AIM: To investigate the value of machine learning-based multiparametric analysis using 2-[18F]-fluoro-2-deoxy-d-glucose positron-emission tomography (FDG-PET) images to predict treatment outcome in patients with oral cavity squamous cell carcinoma (OCSCC). MATERIALS AND METHODS: Ninety-nine patients with OCSCC who received pretreatment integrated FDG-PET/computed tomography (CT) were included. They were divided into the training (66 patients) and validation (33 patients) cohorts. The diagnosis of local control or local failure was obtained from patient's medical records. Conventional FDG-PET parameters, including the maximum and mean standardised uptake values (SUVmax and SUVmean), metabolic tumour volume (MTV), and total lesion glycolysis (TLG), quantitative tumour morphological parameters, intratumoural histogram, and texture parameters, as well as T-stage and clinical stage, were evaluated by a machine learning analysis. The diagnostic ability of T-stage, clinical stage, and conventional FDG-PET parameters (SUVmax, SUVmean, MTV, and TLG) was also assessed separately. RESULTS: In support-vector machine analysis of the training dataset, the final selected parameters were T-stage, SUVmax, TLG, morphological irregularity, entropy, and run-length non-uniformity. In the validation dataset, the diagnostic performance of the created algorithm was as follows: sensitivity 0.82, specificity 0.7, positive predictive value 0.86, negative predictive value 0.64, and accuracy 0.79. In a univariate analysis using conventional FDG-PET parameters, T-stage and clinical stage, diagnostic accuracy of each variable was revealed as follows: 0.61 in T-stage, 0.61 in clinical stage, 0.64 in SUVmax, 0.61 in SUVmean, 0.64 in MTV, and 0.7 in TLG. CONCLUSION: A machine-learning-based approach to analysing FDG-PET images by multiparametric analysis might help predict local control or failure in patients with OCSCC.
• Cystic cervical lymph nodes of papillary thyroid carcinoma, tuberculosis and human papillomavirus positive oropharyngeal squamous cell carcinoma: utility of deep learning in their differentiation on CT.

  Keita Onoue, Noriyuki Fujima, V Carlota Andreu-Arasa, Bindu N Setty, Osamu Sakai

  American journal of otolaryngology 42 5 103026 - 103026 2021年04月09日 

  OBJECTIVES: Cervical lymph nodes with internal cystic changes are seen with several pathologies, including papillary thyroid carcinoma (PTC), tuberculosis (TB), and HPV-positive oropharyngeal squamous cell carcinoma (HPV+OPSCC). Differentiating these lymph nodes is difficult in the absence of a known primary tumor or reliable medical history. In this study, we assessed the utility of deep learning in differentiating the pathologic lymph nodes of PTC, TB, and HPV+OPSCC on CT. METHODS: A total of 173 lymph nodes (55 PTC, 58 TB, and 60 HPV+OPSCC) were selected based on pathology records and suspicious morphological features. These lymph nodes were divided into the training set (n = 131) and the test set (n = 42). In deep learning analysis, JPEG lymph node images were extracted from the CT slice that included the largest area of each node and fed into a deep learning training session to create a diagnostic model. Transfer learning was used with the deep learning model architecture of ResNet-101. Using the test set, the diagnostic performance of the deep learning model was compared against the histopathological diagnosis and to the diagnostic performances of two board-certified neuroradiologists. RESULTS: Diagnostic accuracy of the deep learning model was 0.76 (=32/42), whereas those of Radiologist 1 and Radiologist 2 were 0.48 (=20/42) and 0.41 (=17/42), respectively. Deep learning derived diagnostic accuracy was significantly higher than both of the two neuroradiologists (P < 0.01, respectively). CONCLUSION: Deep learning algorithm holds promise to become a useful diagnostic support tool in interpreting cervical lymphadenopathy.
• Editorial for "Intra-voxel incoherent motion (IVIM) MRI for prediction of induction chemotherapy response in locally advanced hypopharyngeal carcinoma: comparison with model-free dynamic contrast-enhanced MRI".

  Noriyuki Fujima

  Journal of magnetic resonance imaging : JMRI 54 1 101 - 102 2021年03月28日
• Use of magnetic resonance venography for inferior petrosal sinus sampling.

  Kikutaro Tokairin, Toshiya Osanai, Noriyuki Fujima, Kinya Ishizaka, Hiroaki Motegi, Yukitomo Ishi, Hiraku Kameda, Taku Sugiyama, Ken Kazumata, Naoki Nakayama

  The journal of vascular access 23 3 1129729821997263 - 1129729821997263 2021年02月24日 

  BACKGROUND: Inferior petrosal sinus (IPS) sampling (IPSS) is a transvenous interventional procedure performed to diagnose Cushing's disease. The reported IPSS failure rate is approximately 10% because IPS catheter delivery is conducted blindly and is challenging because of IPS anatomical variations. This study aimed to evaluate the usefulness of preprocedural magnetic resonance venography (MRV) for assessing IPS access routes before IPSS. METHODS: Nineteen consecutive patients who underwent IPSS at a single university hospital in Japan were retrospectively studied. A preprocedural MRV protocol optimized to visualize the IPS before IPSS was established and utilized in the eight most recent cases. An IPSS procedure was considered successful when bilateral IPS catheterization was accomplished. Patient demographics, IPSS success rate, and radiation dose required during IPSS were compared between two groups: MRV group (N = 8) and no-MRV group (N = 11) before IPSS. RESULTS: There were no significant differences in age, sex, and IPSS success rates between the groups. The average radiation dose was 663.6 ± 246.8 (SD) mGy and 981.7 ± 389.5 (SD) mGy in the MRV group and no-MRV group, respectively. Thus, there was a significant reduction in radiation exposure in the MRV group (p = 0.044). Catheterization of the left IPS was unsuccessful in only one patient in the MRV group owing to IPS hypoplasty, as found on the MRV. CONCLUSIONS: Hypoplastic IPSs occur in patients and can complicate IPSS. Preprocedural MRV assessment is useful for understanding venous anatomy and preventing unnecessary intravenous catheter manipulation during IPSS, which involves blind manipulation around the IPS.
• Utility of deep learning for the diagnosis of otosclerosis on temporal bone CT.

  Noriyuki Fujima, V Carlota Andreu-Arasa, Keita Onoue, Peter C Weber, Richard D Hubbell, Bindu N Setty, Osamu Sakai

  European radiology 31 7 5206 - 5211 2021年01月06日 

  OBJECTIVE: Diagnosis of otosclerosis on temporal bone CT images is often difficult because the imaging findings are frequently subtle. Our aim was to assess the utility of deep learning analysis in diagnosing otosclerosis on temporal bone CT images. METHODS: A total of 198 temporal bone CT images were divided into the training set (n = 140) and the test set (n = 58). The final diagnosis (otosclerosis-positive or otosclerosis-negative) was determined by an experienced senior radiologist who carefully reviewed all 198 temporal bone CT images while correlating with clinical and intraoperative findings. In deep learning analysis, a rectangular target region that includes the area of the fissula ante fenestram was extracted and fed into the deep learning training sessions to create a diagnostic model. Transfer learning was used with the deep learning model architectures of AlexNet, VGGNet, GoogLeNet, and ResNet. The test data set was subsequently analyzed using these models and by another radiologist with 3 years of experience in neuroradiology following completion of a neuroradiology fellowship. The performance of the radiologist and the deep learning models was determined using the senior radiologist's diagnosis as the gold standard. RESULTS: The diagnostic accuracies were 0.89, 0.72, 0.81, 0.86, and 0.86 for the subspecialty trained radiologist, AlexNet, VGGNet, GoogLeNet, and ResNet, respectively. The performances of VGGNet, GoogLeNet, and ResNet were not significantly different compared to the radiologist. In addition, GoogLeNet and ResNet demonstrated non-inferiority compared to the radiologist. CONCLUSIONS: Deep learning technique may be a useful supportive tool in diagnosing otosclerosis on temporal bone CT. KEY POINTS: • Deep learning can be a helpful tool for the diagnosis of otosclerosis on temporal bone CT. • Deep learning analyses with GoogLeNet and ResNet demonstrate non-inferiority when compared to the subspecialty trained radiologist. • Deep learning may be particularly useful in medical institutions without experienced radiologists.
• Improved Depictions of the Anterior Choroidal Artery and Thalamoperforating Arteries on 3D-CTA Images Using Model-based Iterative Reconstruction.

  Naoko Hamaguchi, Noriyuki Fujima, Akiyoshi Hamaguchi, Shuuichi Kodera

  Academic radiology 28 1 e14-e19  2021年01月 

  RATIONALE AND OBJECTIVES: To evaluate the depictability of intracranial small arteries using high-resolution CTA with model-based iterative reconstruction (MBIR). MATERIALS AND METHODS: We retrospectively analyzed 21 patients who underwent brain 3D-CTA. Axial and volume-rendered (VR) images were reconstructed from the 3D-CTA raw data using adaptive statistical image reconstruction (ASIR) and MBIR. As a quantitative assessment, intra-arterial CT values of the ICA and contrast-to-noise ratio were measured to evaluate vessel enhancement. Additionally, CT values and standard deviations (SDs) of CT values and signal to noise ratio in white matter parenchyma were measured to evaluate background noise. As a qualitative assessment, the degree of vessel depictability in the anterior choroidal artery (AchoA) and the perforating branches of thalamoperforating arteries (TPA) on VR images using two different reconstruction algorithms was visually evaluated using a 3-point grading system. RESULTS: The CT value of the ICA [605.27± 89.76 Hounsfield units (HU)] was significantly increased and the SD value (i.e., image noise) of the white matter parenchyma [6.79 ± 0.81(HU)] was decreased on MBIR compared with ASIR [546.76 ± 85.27 (HU)] and [8.04 ± 1.08 HU)] (p <.05 for all). Contrast-to-noise ratio of ICA [84.48 ± 20.17] and signal to noise ratio of white matter [6.18 ± 0.75] with MBIR were significantly higher than ASIR [65.98 ± 13.08] and [5.28 ± 0.78] (p < 0.05 for all). In addition, depictions of the AchoA and TPA on VR images were significantly improved using MBIR compared with ASIR (p < 0.05). CONCLUSION: MBIR allows depiction of small intracranial arteries such as AchoA and TPA with better visibility than ASIR without increasing the dose of radiation and the amount of contrast agent.
• Multiparametric Analysis of Tumor Morphological and Functional MR Parameters Potentially Predicts Local Failure in Pharynx Squamous Cell Carcinoma Patients.

  Noriyuki Fujima, Yukie Shimizu, Daisuke Yoshida, Satoshi Kano, Takatsugu Mizumachi, Akihiro Homma, Koichi Yasuda, Rikiya Onimaru, Osamu Sakai, Kohsuke Kudo, Hiroki Shirato

  The journal of medical investigation : JMI 68 3.4 354 - 361 2021年 

  Purpose : To predict local control / failure by a multiparametric approach using magnetic resonance (MR)-derived tumor morphological and functional parameters in pharynx squamous cell carcinoma (SCC) patients. Materials and Methods : Twenty-eight patients with oropharyngeal and hypopharyngeal SCCs were included in this study. Quantitative morphological parameters and intratumoral characteristics on T2-weighted images, tumor blood flow from pseudo-continuous arterial spin labeling, and tumor diffusion parameters of three diffusion models from multi-b-value diffusion-weighted imaging as well as patients' characteristics were analyzed. The patients were divided into local control / failure groups. Univariate and multiparametric analysis were performed for the patient group division. Results : The value of morphological parameter of 'sphericity' and intratumoral characteristic of 'homogeneity' was revealed respectively significant for the prediction of the local control status in univariate analysis. Higher diagnostic performance was obtained with the sensitivity of 0.8, specificity of 0.75, positive predictive value of 0.89, negative predictive value of 0.6 and accuracy of 0.79 by multiparametric diagnostic model compared to results in the univariate analysis. Conclusion : A multiparametric analysis with MR-derived quantitative parameters may be useful to predict local control in pharynx SCC patients. J. Med. Invest. 68 : 354-361, August, 2021.
• Analysis of acute-phase toxicities of intensity-modulated proton therapy using a model-based approach in pharyngeal cancer patients.

  Koichi Yasuda, Hideki Minatogawa, Yasuhiro Dekura, Seishin Takao, Masaya Tamura, Nayuta Tsushima, Takayoshi Suzuki, Satoshi Kano, Takatsugu Mizumachi, Takashi Mori, Kentaro Nishioka, Motoyasu Shido, Norio Katoh, Hiroshi Taguchi, Noriyuki Fujima, Rikiya Onimaru, Isao Yokota, Keiji Kobashi, Shinichi Shimizu, Akihiro Homma, Hiroki Shirato, Hidefumi Aoyama

  Journal of radiation research 62 2 329 - 337 2020年12月29日 

  Pharyngeal cancer patients treated with intensity-modulated proton therapy (IMPT) using a model-based approach were retrospectively reviewed, and acute toxicities were analyzed. From June 2016 to March 2019, 15 pharyngeal (7 naso-, 5 oro- and 3 hypo-pharyngeal) cancer patients received IMPT with robust optimization. Simulation plans for IMPT and intensity-modulated X-ray therapy (IMXT) were generated before treatment. We also reviewed 127 pharyngeal cancer patients with IMXT in the same treatment period. In the simulation planning comparison, all of the normal-tissue complication probability values for dysphagia, dysgeusia, tube-feeding dependence and xerostomia were lower for IMPT than for IMXT in the 15 patients. After completing IMPT, 13 patients completed the evaluation, and 12 of these patients had a complete response. The proportions of patients who experienced grade 2 or worse acute toxicities in the IMPT and IMXT cohorts were 21.4 and 56.5% for dysphagia (P < 0.05), 46.7 and 76.3% for dysgeusia (P < 0.05), 73.3 and 62.8% for xerostomia (P = 0.43), 73.3 and 90.6% for mucositis (P = 0.08) and 66.7 and 76.4% for dermatitis (P = 0.42), respectively. Multivariate analysis revealed that IMPT was independently associated with a lower rate of grade 2 or worse dysphagia and dysgeusia. After propensity score matching, 12 pairs of IMPT and IMXT patients were selected. Dysphagia was also statistically lower in IMPT than in IMXT (P < 0.05). IMPT using a model-based approach may have clinical benefits for acute dysphagia.
• Potential benefits of adaptive intensity-modulated proton therapy in nasopharyngeal carcinomas.

  Hideki Minatogawa, Koichi Yasuda, Yasuhiro Dekura, Seishin Takao, Taeko Matsuura, Takaaki Yoshimura, Ryusuke Suzuki, Isao Yokota, Noriyuki Fujima, Rikiya Onimaru, Shinichi Shimizu, Hidefumi Aoyama, Hiroki Shirato

  Journal of applied clinical medical physics 22 1 174 - 183 2020年12月18日 

  PURPOSE: To investigate potential advantages of adaptive intensity-modulated proton beam therapy (A-IMPT) by comparing it to adaptive intensity-modulated X-ray therapy (A-IMXT) for nasopharyngeal carcinomas (NPC). METHODS: Ten patients with NPC treated with A-IMXT (step and shoot approach) and concomitant chemotherapy between 2014 and 2016 were selected. In the actual treatment, 46 Gy in 23 fractions (46Gy/23Fx.) was prescribed using the initial plan and 24Gy/12Fx was prescribed using an adapted plan thereafter. New treatment planning of A-IMPT was made for the same patients using equivalent dose fractionation schedule and dose constraints. The dose volume statistics based on deformable images and dose accumulation was used in the comparison of A-IMXT with A-IMPT. RESULTS: The means of the Dmean of the right parotid gland (P < 0.001), right TM joint (P < 0.001), left TM joint (P < 0.001), oral cavity (P < 0.001), supraglottic larynx (P = 0.001), glottic larynx (P < 0.001), , middle PCM (P = 0.0371), interior PCM (P < 0.001), cricopharyngeal muscle (P = 0.03643), and thyroid gland (P = 0.00216), in A-IMPT are lower than those of A-IMXT, with statistical significance. The means of, D0.03cc , and Dmean of each sub portion of auditory apparatus and D30% for Eustachian tube and D0.5cc for mastoid volume in A-IMPT are significantly lower than those of A-IMXT. The mean doses to the oral cavity, supraglottic larynx, and glottic larynx were all reduced by more than 20 Gy (RBE = 1.1). CONCLUSIONS: An adaptive approach is suggested to enhance the potential benefit of IMPT compared to IMXT to reduce adverse effects for patients with NPC.
• Reinterpretation of magnetic resonance imaging findings with magnetoencephalography can improve the accuracy of detecting epileptogenic cortical lesions.

  Kosuke Otsuka, Kiyoshi Egawa, Noriyuki Fujima, Kohsuke Kudo, Satoshi Terae, Midori Nakajima, Tomoshiro Ito, Kazuyori Yagyu, Hideaki Shiraishi

  Epilepsy & behavior : E&B 114 Pt A 107516 - 107516 2020年12月12日 

  OBJECTIVE: This study examined whether the application of magnetoencephalography (MEG) to interpret magnetic resonance imaging (MRI) findings can aid the diagnosis of intractable epilepsy caused by organic brain lesions. METHODS: This study included 51 patients with epilepsy who had MEG clusters but whose initial MRI findings were interpreted as being negative for organic lesions. Three board-certified radiologists reinterpreted the MRI findings, utilizing the MEG findings as a guide. The degree to which the reinterpretation of the imaging results identified an organic lesion was rated on a 5-point scale. RESULTS: Reinterpretation of the MRI data with MEG guidance helped detect an abnormality by at least one radiologist in 18 of the 51 patients (35.2%) with symptomatic localization-related epilepsy. A surgery was performed in 7 of the 51 patients, and histopathological analysis results identified focal cortical dysplasia in 5 patients (Ia: 1, IIa: 2, unknown: 2), hippocampal sclerosis in 1 patient, and dysplastic neurons/gliosis in 1 patient. CONCLUSIONS: The results of this study highlight the potential diagnostic applications of MEG to detect organic epileptogenic lesions, particularly when radiological visualization is difficult with MRI alone.
• Intracranial 3D and 4D MR Angiography Using Arterial Spin Labeling: Technical Considerations.

  Yuriko Suzuki, Noriyuki Fujima, Matthias J P van Osch

  Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 19 4 294 - 309 2020年12月01日 

  In the 1980's some of the earliest studies of arterial spin labeling (ASL) MRI have demonstrated its ability to generate MR angiography (MRA) images. Thanks to many technical improvements, ASL has been successfully moving its position from the realm of research into the clinical area, albeit more known as perfusion imaging than as MRA. For MRA imaging, other techniques such as time-of-flight, phase contrast MRA and contrast-enhanced (CE) MRA are more popular choices for clinical applications. In the last decade, however, ASL-MRA has been experiencing a remarkable revival, especially because of its non-invasive nature, i.e. the fact that it does not rely on the use of contrast agent. Very importantly, there are additional benefits of using ASL for MRA. For example, its higher flexibility to achieve both high spatial and temporal resolution than CE dynamic MRA, and the capability of vessel specific visualization, in which the vascular tree arising from a selected artery can be exclusively visualized. In this article, the implementation and recent developments of ASL-based MRA are discussed; not only focusing on the basic sequences based upon pulsed ASL or pseudo-continuous ASL, but also including more recent labeling approaches, such as vessel-selective labeling, velocity-selective ASL, vessel-encoded ASL and time-encoded ASL. Although these ASL techniques have been already utilized in perfusion imaging and their usefulness has been suggested by many studies, some additional considerations should be made when employing them for MRA, since there is something more than the difference of the spatial resolution of the readout sequence. Moreover, extensive discussion is included on what readout sequence to use, especially by highlighting how to achieve high spatial resolution while keeping scan-time reasonable such that the ASL-MRA sequence can easily be included into a clinical examination.
• Deep learning analysis using FDG-PET to predict treatment outcome in patients with oral cavity squamous cell carcinoma.

  Noriyuki Fujima, V Carlota Andreu-Arasa, Sara K Meibom, Gustavo A Mercier, Andrew R Salama, Minh Tam Truong, Osamu Sakai

  European radiology 30 11 6322 - 6330 2020年11月 [査読有り][通常論文]
   

  OBJECTIVE: To assess the utility of deep learning analysis using 18F-fluorodeoxyglucose (FDG) uptake by positron emission tomography (PET/CT) to predict disease-free survival (DFS) in patients with oral cavity squamous cell carcinoma (OCSCC). METHODS: One hundred thirteen patients with OCSCC who received pretreatment FDG-PET/CT were included. They were divided into training (83 patients) and test (30 patients) sets. The diagnosis of treatment control/failure and the DFS rate were obtained from patients' medical records. In deep learning analyses, three planes of axial, coronal, and sagittal FDG-PET images were assessed by ResNet-101 architecture. In the training set, image analysis was performed for the diagnostic model creation. The test data set was subsequently analyzed for confirmation of diagnostic accuracy. T-stage, clinical stage, and conventional FDG-PET parameters (the maximum and mean standardized uptake value (SUVmax and SUVmean), heterogeneity index, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were also assessed with determining the optimal cutoff from training dataset and then validated their diagnostic ability from test dataset. RESULTS: In dividing into patients with treatment control and failure, the highest diagnostic accuracy of 0.8 was obtained using deep learning classification, with a sensitivity of 0.8, specificity of 0.8, positive predictive value of 0.89, and negative predictive value of 0.67. In the Kaplan-Meier analysis, the DFS rate was significantly different only with the analysis of deep learning-based classification (p < .01). CONCLUSIONS: Deep learning-based diagnosis with FDG-PET images may predict treatment outcome in patients with OCSCC. KEY POINTS: • Deep learning-based diagnosis of FDG-PET images showed the highest diagnostic accuracy to predict the treatment outcome in patients with oral cavity squamous cell carcinoma. • Deep learning-based diagnosis was shown to differentiate patients between good and poor disease-free survival more clearly than conventional T-stage, clinical stage, and conventional FDG-PET-based parameters.
• Cystic cervical lymph nodes of papillary thyroid carcinoma, tuberculosis and human papillomavirus positive oropharyngeal squamous cell carcinoma: Comparative CT analysis for their differentiation.

  Keita Onoue, Noriyuki Fujima, V Carlota Andreu-Arasa, Bindu N Setty, Muhammad Mustafa Qureshi, Osamu Sakai

  European journal of radiology 132 109310 - 109310 2020年10月01日 

  PURPOSE: Cervical lymph nodes with cystic changes are an important finding seen with several pathologies including papillary thyroid carcinoma (PTC), tuberculosis (TB) and HPV-positive oropharyngeal squamous cell carcinoma (HPV + OPSCC). In the absence of known primary tumor or conclusive medical history, differentiating among these nodes is difficult. We compared the pathologic nodes of PTC, TB and HPV + OPSCC to identify imaging features useful for their differentiation. MATERIALS AND METHODS: Fifty-five PTC, 58 TB and 51 HPV + OPSCC nodes were selected based on surgical pathology records and suspicious morphological features. These nodes were compared for morphological features: long axis length, nodal shape, nodal location, presence of cystic change, area of cystic change:area of entire node ratio, Hounsfield unit of the cystic component, degree of enhancement, enhancement pattern, presence of calcification, presence of perinodal infiltration, and presence of surrounding inflammatory changes. RESULTS: PTC nodes formed calcifications more frequently and demonstrated greater enhancement (P < 0.01). TB nodes were characterized by their irregular shape (P < 0.05), irregular enhancement surrounding the cystic change (P < 0.01), greater frequencies of perinodal infiltration (P < 0.01) and surrounding inflammatory changes (P < 0.01). While no unique features were seen with HPV+OPSCC, they were characterized by the absence of those features that distinguished the other groups: these nodes tended to have smooth, circumscribed margins with no hyperenhancement, calcifications or inflammatory changes. PTC and TB nodes were more frequently identified in the lower neck, while HPV+OPSCC nodes were localized to the upper neck (P < 0.01). CONCLUSIONS: PTC, TB and HPV + OPSCC lymph nodes can be differentiated based on their morphologies and locations.
• Risk assessment of osteoradionecrosis associated with periodontitis using 18F-FDG PET/CT.

  Kotaro Ito, Koji Takumi, Sara K Meibom, Muhammad Mustafa Qureshi, Noriyuki Fujima, V Carlota Andreu-Arasa, Minh Tam Truong, Andrew R Salama, Takashi Kaneda, Osamu Sakai

  European journal of radiology 132 109259 - 109259 2020年09月04日 

  PURPOSE: Osteoradionecrosis (ORN) is a serious complication after radiotherapy (RT), even in the era of intensity modulated radiation therapy (IMRT). The purpose of this study was to evaluate whether 18F-FDG PET/CT can predict ORN associated with periodontal disease in patients with oropharyngeal or oral cavity squamous cell carcinoma (OP/OC SCC) undergoing RT. METHODS: One hundred and five OP/OC SCC patients treated with RT who underwent pretreatment 18F-FDG PET/CT between October 2007 and June 2016 were retrospectively reviewed. A post-treatment diagnosis of ORN was made clinically based on presence of exposed irradiated mandibular bone that failed to heal after a period of three months without persistent or recurrent tumor. The maximum standardized uptake value (SUVmax) of periodontal regions identified on PET/CT was measured for all patients. Image-based staging of periodontitis was also performed using American Academy of Periodontology staging system on CT. RESULTS: Among 105 patients, 14 (13.3 %) developed ORN. The SUVmax of the periodontal region in patients with ORN (3.35 ± 1.23) was significantly higher than patients without ORN (1.92 ± 0.66) (P <  .01). The corresponding CT stage of periodontitis in patients with ORN was significantly higher (2.71±0.47) than patients without ORN (1.80±0.73) (P <  .01). ROC analysis revealed the cut-off values of developing ORN were 2.1 in SUVmax, and II in CT stage of periodontitis. The corresponding AUC was 0.86 and 0.82, respectively. CONCLUSIONS: Pretreatment 18F-FDG PET/CT identification of periodontitis may be helpful to predict the future development of ORN in patients with OP/OC SCC undergoing RT.
• Magnetic Resonance Spectroscopy of the Head and Neck: Principles, Applications, and Challenges.

  Noriyuki Fujima, V Carlota Andreu-Arasa, Glenn D Barest, Ashok Srinivasan, Osamu Sakai

  Neuroimaging clinics of North America 30 3 283 - 293 2020年08月 

  Several investigations have revealed the utility of magnetic resonance spectroscopy (MRS) as an adjunct in the evaluation of lesions of the head and neck. This technique remains a challenge in the head and neck because of its low signal-to-noise ratio and long acquisition times. In this review article, the basics of image acquisition technique and reported clinical utilities of head and neck MRS are presented.
• Utility of a diffusion-weighted arterial spin labeling (DW-ASL) technique for evaluating the progression of brain white matter lesions.

  Noriyuki Fujima, Hiroyuki Kameda, Yukie Shimizu, Taisuke Harada, Khin Khin Tha, Masami Yoneyama, Kohsuke Kudo

  Magnetic resonance imaging 69 81 - 87 2020年06月 [査読有り][通常論文]
   

  PURPOSE: To investigate the utility of diffusion-weighted arterial spin labeling (DW-ASL) for detecting the progression of brain white matter lesions. MATERIALS AND METHODS: A total of 492 regions of interest (ROIs) in 41 patients were prospectively analyzed. DW-ASL was performed using the diffusion gradient prepulse of five b-values (0, 25, 60, 102, and 189) before the ASL readout. We calculated the water exchange rate (Kw) with post-processing using the ASL signal information for each b-value. The cerebral blood flow (CBF) was also calculated using b0 images. Using the signal information in FLAIR (fluid-attenuated inversion recovery) images, we classified the severity of white matter lesions into three grades: non-lesion, moderate, and severe. In addition, the normal Kw level was measured from DW-ASL data of 60 ROIs in five control subjects. The degree of variance of the Kw values (Kw-var) was calculated by squaring the value of the difference between each Kw value and the normal Kw level. All patient's ROIs were divided into non-progressive and progressive white matter lesions by comparing the present FLAIR images with those obtained 2 years before this acquisition. RESULTS: Compared to the non-progressive group, the progressive group had significantly lower CBF, significantly higher severity grades in FLAIR, and significantly greater Kw-var values. In a receiver operator characteristic curve analysis, a high area under the curve (AUC) of 0.89 was obtained with the use of Kw-var. In contrast, the AUCs of 0.59 for CBF and 0.72 for severity grades in FLAIR were obtained. CONCLUSIONS: The DW-ASL technique can be useful to detect the progression of brain white matter lesions. This technique will become a clinical tool for patients with various degrees of white matter lesions.
• Prediction of the human papillomavirus status in patients with oropharyngeal squamous cell carcinoma by FDG-PET imaging dataset using deep learning analysis: A hypothesis-generating study.

  Noriyuki Fujima, V Carlota Andreu-Arasa, Sara K Meibom, Gustavo A Mercier, Minh Tam Truong, Osamu Sakai

  European journal of radiology 126 108936 - 108936 2020年05月 

  PURPOSE: To assess the diagnostic accuracy of imaging-based deep learning analysis to differentiate between human papillomavirus (HPV) positive and negative oropharyngeal squamous cell carcinomas (OPSCCs) using FDG-PET images. METHODS: One hundred and twenty patients with OPSCC who underwent pretreatment FDG-PET/CT were included and divided into the training 90 patients and validation 30 patients cohorts. In the training session, 2160 FDG-PET images were analyzed after data augmentation process by a deep learning technique to create a diagnostic model to discriminate between HPV-positive and HPV-negative OPSCCs. Validation cohort data were subsequently analyzed for confirmation of diagnostic accuracy in determining HPV status by the deep learning-based diagnosis model. In addition, two radiologists evaluated the validation cohort image-data to determine the HPV status based on each tumor's imaging findings. RESULTS: In deep learning analysis with training session, the diagnostic model using training dataset was successfully created. In the validation session, the deep learning diagnostic model revealed sensitivity of 0.83, specificity of 0.83, positive predictive value of 0.88, negative predictive value of 0.77, and diagnostic accuracy of 0.83, while the visual assessment by two radiologists revealed 0.78, 0.5, 0.7, 0.6, and 0.67 (reader 1), and 0.56, 0.67, 0.71, 0.5, and 0.6 (reader 2), respectively. Chi square test showed a significant difference between deep learning- and radiologist-based diagnostic accuracy (reader 1: P = 0.016, reader 2: P = 0.008). CONCLUSIONS: Deep learning diagnostic model with FDG-PET imaging data can be useful as one of supportive tools to determine the HPV status in patients with OPSCC.
• Evaluation of non-Gaussian model-based diffusion-weighted imaging in oral squamous cell carcinoma: comparison with tumour functional information derived from positron-emission tomography.

  T Shima, N Fujima, S Yamano, K Kudo, K Hirata, K Minowa

  Clinical radiology 75 5 397.e15-397.e21  2020年05月 [査読有り][通常論文]
   

  AIM: To evaluate and compare diffusion-weighted imaging (DWI) parameters derived from a non-Gaussian fitting model and positron-emission tomography (PET) parameters derived from 18F-fluoromisonidazole-PET (FMISO-PET) in patients with oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: Primary sites were evaluated prospectively in 18 patients. DWI was performed using six b-values (0-2,500). Diffusion-related parameters of kurtosis value (K), the kurtosis-corrected diffusion coefficient (DK), diffusion heterogeneity (α), distributed diffusion coefficient (DDC), the slow diffusion coefficient (Dslow), and the apparent diffusion coefficient (ADC) were calculated from four diffusion-fitting models. Maximal standardised uptake values (SUVmax), mean standardised uptake values (SUVmean), and the tumour-to-muscle ration (TMR) of the SUV value were calculated for FMISO-PET. Spearman's correlation coefficient was used to evaluate the correlation between each non-Gaussian diffusion model parameters and PET parameter. RESULTS: There was moderate correlation between FMISO-PET SUVmax and Dslow (ρ=-0.45, p=0.06). In addition, there was good correlation between TMRmax and five non-Gaussian diffusion model parameters (K: ρ=0.65, p=0.004, DK: ρ=-0.72, p=0.0008, DDC: ρ=-0.75, p=0.0003, ADC: ρ=-0.74, p=0.0005, and Dslow: ρ= -0.65, p=0.003), and between TMRmean and five non-Gaussian model parameters (K: ρ=0.64, p=0.005, DK: ρ=-0.61, p=0.007, DDC: ρ=-0.63, p=0.005, ADC: ρ=-0.61, p=0.007, and Dslow: ρ=-0.56, p=0.015). CONCLUSION: Non-Gaussian diffusion model parameters can be related to tumour hypoxia.
• Microstructural Alterations in Bipolar and Major Depressive Disorders: A Diffusion Kurtosis Imaging Study.

  Daisuke Sawamura, Hisashi Narita, Naoki Hashimoto, Shin Nakagawa, Hiroyuki Hamaguchi, Noriyuki Fujima, Kohsuke Kudo, Hiroki Shirato, Khin K Tha

  Journal of magnetic resonance imaging : JMRI 52 4 1187 - 1196 2020年04月23日 [査読有り][通常論文]
   

  BACKGROUND: Identifying structural and functional abnormalities in bipolar (BD) and major depressive disorders (MDD) is important for understanding biological processes. HYPOTHESIS: Diffusion kurtosis imaging (DKI) may be able to detect the brain's microstructural alterations in BD and MDD and any differences between the two. STUDY TYPE: Prospective. SUBJECTS: In all, 16 BD patients, 19 MDD patients, and 20 age- and gender-matched healthy volunteers. FIELD STRENGTH/SEQUENCE: DKI at 3.0T. ASSESSMENT: The major DKI indices of the brain were compared voxel-by-voxel among the three groups. Significantly different voxels were tested for correlation with clinical variables (ie, Young Mania Rating Scale [YMRS], 17-item Hamilton Depression Rating Scale [17-HDRS], Montgomery-Åsberg Depression Rating Scale, total disease duration, duration of current episode, and the number of past manic/depressive episodes). The performance of the DKI indices in identifying microstructural alterations was estimated. STATISTICAL TESTS: One-way analysis of variance (ANOVA) was used for group comparison of DKI indices. The performance of these indices in detecting microstructural alterations was determined by receiver operating characteristic (ROC) analysis. Pearson's product-moment correlation analyses were used to test the correlations of these indices with clinical variables. RESULTS: DKI revealed widespread microstructural alterations across the brain in each disorder (P < 0.05). Some were significantly different between the two disorders. Mean kurtosis (MK) in the gray matter of the right inferior parietal lobe was able to distinguish BD and MDD with an accuracy of 0.906. A strong correlation was revealed between MK in that region and YMRS in BD patients (r = -0.641, corrected P = 0.042) or 17-HDRS in MDD patients (r = -0.613, corrected P = 0.030). There were also strong correlations between a few other DKI indices and disease duration (r = -0.676 or 0.626, corrected P < 0.05). DATA CONCLUSION: DKI detected microstructural brain alterations in BD and MDD. Its indices may be useful to distinguish the two disorders or to reflect disease severity and duration. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 3.
• Delivering the diluted contrast agent with saline via a spiral flow tube improves arterial enhancement for contrast enhancement of magnetic resonance angiography of the neck: A retrospective study.

  Akiyoshi Hamaguchi, Noriyuki Fujima, Naoko Hamaguchi, Tetsuji Hayashi, Shuichi Kodera

  Medicine 98 52 e18526  2019年12月 

  A contrast agent can be pushed by a saline solution more effectively through a spiral flow tube than through a conventional T-shaped tube in contrast-enhanced magnetic resonance angiography (CEMRA). To compare the degree of contrast enhancement and signal stability in the carotid artery by using CEMRA between a spiral flow tube and a T-shaped tube.A total of 100 patients were analyzed in this retrospective study. The first 50 patients underwent CEMRA of the carotid artery with the T-shaped tube, while the last 50 patients used the spiral flow tube. Gadoterate meglumine was diluted with saline to make a total volume of 20 mL. Injection was performed with a bolus rate of 2.5 mL/s for 8 seconds. Five regions of interest (ROIs) were placed on the contrast-enhanced area in each carotid artery and the signal intensity (SI) in the ROI was used for the analysis. The ROIs on the brain stem were also placed and the average SI in this ROI was used as a reference signal. The enhancement of the artery (Eartery) was calculated as a normalized signal using the following equation: Eartery = SI in the ROI of the carotid bifurcation/SI in the ROI of the brain stem. Signal homogeneity in the contrast-enhanced area (SHenhance) was assessed by calculating the coefficient of variation from the SI in the 5 ROIs. The value of SHenhance and Eartery between the data obtained from the spiral flow tube and the T-shaped tube were compared. P-values <.05 were considered significant.We found a significant difference in SHenhance between the data obtained from the spiral flow tube (0.20 ± 0.060) and the T-shaped tube (0.24 ± 0.056) (P = .001). The Eartery values significantly increased by 15% (spiral flow tube, median 14.1 with interquartile range [IQR] 11.8-15.4 vs T-shaped tube, median 12.3 IQR 11.3-14.0, P = .02) using the spiral flow tube.These findings suggest that, by using the Spiral flow tube, the homogeneity of the contrast-enhanced signal intensity in the carotid artery was significantly improved without decreasing the signal intensity in CEMRA.
• Prediction of Hypoxia in Brain Tumors Using a Multivariate Model Built from MR Imaging and ¹⁸F-Fluorodeoxyglucose Accumulation Data.

  Shimizu Y, Kudo K, Kameda H, Harada T, Fujima N, Toyonaga T, Tha KK, Shirato H

  Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 19 3 227 - 234 2019年10月 [査読有り][通常論文]
   

  PURPOSE: The aim of this study was to generate a multivariate model using various MRI markers of blood flow and vascular permeability and accumulation of 18F-fluorodeoxyglucose (FDG) to predict the extent of hypoxia in an 18F-fluoromisonidazole (FMISO)-positive region. METHODS: Fifteen patients aged 27-74 years with brain tumors (glioma, n = 13; lymphoma, n = 1; germinoma, n = 1) were included. MRI scans were performed using a 3T scanner, and dynamic contrast-enhanced (DCE) perfusion and arterial spin labeling images were obtained. Ktrans and Vp maps were generated using the DCE images. FDG and FMISO positron emission tomography scans were also obtained. A model for predicting FMISO positivity was generated on a voxel-by-voxel basis by a multivariate logistic regression model using all the MRI parameters with and without FDG. Receiver-operating characteristic curve analysis was used to detect FMISO positivity with multivariate and univariate analysis of each parameter. Cross-validation was performed using the leave-one-out method. RESULTS: The area under the curve (AUC) was highest for the multivariate prediction model with FDG (0.892) followed by the multivariate model without FDG and univariate analysis with FDG and Ktrans (0.844 for all). In cross-validation, the multivariate model with FDG had the highest AUC (0.857 ± 0.08) followed by the multivariate model without FDG (0.834 ± 0.119). CONCLUSION: A multivariate prediction model created using blood flow, vascular permeability, and glycometabolism parameters can predict the extent of hypoxia in FMISO-positive areas in patients with brain tumors.
• Acceleration of vessel-selective dynamic MR Angiography by pseudocontinuous arterial spin labeling in combination with Acquisition of ConTRol and labEled images in the Same Shot (ACTRESS).

  Yuriko Suzuki, Thomas W Okell, Noriyuki Fujima, Matthias J P van Osch

  Magnetic resonance in medicine 81 5 2995 - 3006 2019年05月 

  PURPOSE: The recently introduced "Acquisition of ConTRol and labEled imaging in the Same Shot" (ACTRESS) approach was designed to halve the scan time of arterial spin labeling (ASL) -based 4D-MRA by obtaining both labeled and control images in a single Look-Locker readout. However, application for vessel-selective labeling remains difficult. The aim of this study was to achieve a combination of ACTRESS and vessel-selective labeling to halve the scan time of vessel-selective 4D-MRA. METHODS: By Bloch equation simulations, Look-Locker pseudocontinuous-ASL (pCASL) was optimized to achieve constant static tissue signal across the multidelay readout, which is essential for the ACTRESS approach. Additionally, a new subtraction scheme was proposed to achieve visualization of the inflow phase even when labeled blood will have already arrived in the distal arteries during the first phase acquisition due to the long duration of the pCASL labeling module. In vivo studies were performed to investigate the signal variation of the static tissue, as well as to assess image quality of vessel-selective 4D-MRA with ACTRESS. RESULTS: In in vivo studies, the mean signal variation of the static tissue was 8.98% over the Look-Locker phases, thereby minimizing the elevation of background signal. This allowed visualization of peripheral arteries and slowly arriving arterial blood with image quality as good as conventional pCASL within half the acquisition time. Vessel-selective pCASL-ACTRESS enabled the separated visualization of vessels arising from internal and external carotid arteries within this shortened acquisition time. CONCLUSION: By combining vessel-selective pCASL and ACTRESS approach, 4D-MRA of a single targeted arterial tree was achieved in a few minutes.
• Non-invasive three-dimensional bone-vessel image fusion using black bone MRI based on FIESTA-C.

  T Hayashi, N Fujima, A Hamaguchi, T Masuzuka, K Hida, S Kodera

  Clinical radiology 74 4 326.e15-326.e21  2019年04月 

  AIM: To evaluate the image quality of bone-vessel fused volume-rendering (VR) images reconstructed by three-dimensional "black bone" magnetic resonance imaging (MRI) based on the fast imaging employing steady-state acquisition cycled phases (FIESTA-C) sequence and time-of-flight magnetic resonance angiography (TOF-MRA). MATERIALS AND METHODS: Seventeen patients were analysed in this retrospective study. All patients underwent both MRI techniques including FIESTA-C and TOF-MRA and computed tomography angiography (CTA). MRI- and CT-based bone-vessel VR images were reconstructed. Visual depictions of frontal and parietal branches from the superficial temporal artery (STA) were independently scored by three experienced radiological technologists using a four-grade system. RESULTS: In the visual evaluation, the scores of the both right and left frontal branches in MRI-based VR image were significantly larger those at CT (p<0.01, respectively). The scores of both the right and left parietal branches tended to be larger in MRI-based than that in CT-based VR imaging, but were not significantly so (p=0.06, 0.13 respectively). In the interobserver agreement analysis, κ values were all good (range: 0.6-0.76) for STA branch evaluation in MRI-based VR images. CONCLUSION: MRI bone-vessel fused VR imaging can non-invasively depict STA frontal branches with better visibility compared to the CT-based VR imaging. This technique may be useful for the preoperative evaluation of donor branches for STA-middle cerebral artery bypass surgery.
• The utility of MRI histogram and texture analysis for the prediction of histological diagnosis in head and neck malignancies

  Fujima Noriyuki, Homma Akihiro, Harada Taisuke, Shimizu Yukie, Tha Khin Khin, Kano Satoshi, Mizumachi Takatsugu, Li Ruijiang, Kudo Kohsuke, Shirato Hiroki

  CANCER IMAGING 19 2019年02月04日 [査読有り][通常論文]
  
• The utility of MRI histogram and texture analysis for the prediction of histological diagnosis in head and neck malignancies.

  Fujima N, Homma A, Harada T, Shimizu Y, Tha KK, Kano S, Mizumachi T, Li R, Kudo K, Shirato H

  Cancer imaging : the official publication of the International Cancer Imaging Society 19 1 5 - 5 2019年02月 [査読有り][通常論文]
   

  BACKGROUND: To assess the utility of histogram and texture analysis of magnetic resonance (MR) fat-suppressed T2-weighted imaging (Fs-T2WI) for the prediction of histological diagnosis of head and neck squamous cell carcinoma (SCC) and malignant lymphoma (ML). METHODS: The cases of 57 patients with SCC (45 well/moderately and 12 poorly differentiated SCC) and 10 patients with ML were retrospectively analyzed. Quantitative parameters with histogram features (relative mean signal, coefficient of variation, kurtosis and skewness) and gray-level co-occurrence matrix (GLCM) features (contrast, correlation, energy and homogeneity) were calculated using Fs-T2WI data with a manual tumor region of interest (ROI). RESULTS: The following significantly different values were obtained for the total SCC versus ML groups: relative mean signal (3.65 ± 0.86 vs. 2.61 ± 0.49), contrast (72.9 ± 16.2 vs. 49.3 ± 8.7) and homogeneity (2.22 ± 0.25 × 10- 1 vs. 2.53 ± 0.12 × 10- 1). In the comparison of the SCC histological grades, the relative mean signal and contrast were significantly lower in the poorly differentiated SCC (2.89 ± 0.63, 56.2 ± 12.9) compared to the well/moderately SCC (3.85 ± 0.81, 77.5 ± 13.9). The homogeneity in poorly differentiated SCC (2.56 ± 0.15 × 10- 1) was higher than that of the well/moderately SCC (2.1 ± 0.18 × 10- 1). CONCLUSIONS: Parameters obtained by histogram and texture analysis of Fs-T2WI may be useful for noninvasive prediction of histological type and grade in head and neck malignancy.
• Optimization of the spatial modulation function of vessel-encoded pseudo-continuous arterial spin labeling and its application to dynamic angiography.

  Yuriko Suzuki, Matthias J P van Osch, Noriyuki Fujima, Thomas W Okell

  Magnetic resonance in medicine 81 1 410 - 423 2019年01月 

  PURPOSE: In vessel-encoded pseudo-continuous arterial spin labeling (ve-pCASL), vessel-selective labeling is achieved by modulation of the inversion efficiency across space. However, the spatial transition between the labeling and control conditions is rather gradual, which can cause partial labeling of vessels, reducing SNR-efficiency and necessitating complex postprocessing to decode the vessel-selective signals. The purpose of this study is to optimize the pCASL labeling parameters to obtain a sharper spatial inversion profile of the labeling and thereby minimizing the risk of partial labeling of untargeted arteries. METHODS: Bloch simulations were performed to investigate how the inversion profile was influenced by the pCASL labeling parameters: the maximum (Gmax ) and mean (Gmean ) labeling gradient were varied for ve-pCASL with unipolar and bipolar gradients. The findings in the simulation study were subsequently confirmed in an in vivo volunteer study. Moreover, conventional and optimized settings were compared for 4D-MRA using four-cycle Hadamard ve-pCASL; the visualization of arteries and the presence of the partial labeling were assessed by an expert observer. RESULTS: When using unipolar gradient, lower Gmean resulted in a steeper spatial transition, whereas the width of the control region was broader for higher Gmax . The in vivo study confirmed these findings. When using bipolar gradients, the control region was always very narrow. Qualitative comparison of the 4D-MRA demonstrated lower occurrence of partial labeling when using the optimized gradient parameters. CONCLUSION: The shape of the ve-pCASL inversion profile can be optimized by changing Gmean and Gmax to reduce partial labeling of untargeted arteries.
• Machine-learning-based prediction of treatment outcomes using MR imaging-derived quantitative tumor information in patients with sinonasal squamous cell carcinomas: A preliminary study

  Noriyuki Fujima, Yukie Shimizu, Daisuke Yoshida, Satoshi Kano, Takatsugu Mizumachi, Akihiro Homma, Koichi Yasuda, Rikiya Onimaru, Osamu Sakai, Kohsuke Kudo, Hiroki Shirato

  Cancers 11 6 2019年 [査読有り][通常論文]
   

  © 2019 by the authors. Licensee MDPI, Basel, Switzerland. The purpose of this study was to determine the predictive power for treatment outcome of a machine-learning algorithm combining magnetic resonance imaging (MRI)-derived data in patients with sinonasal squamous cell carcinomas (SCCs). Thirty-six primary lesions in 36 patients were evaluated. Quantitative morphological parameters and intratumoral characteristics from T2-weighted images, tumor perfusion parameters from arterial spin labeling (ASL) and tumor diffusion parameters of five diffusion models from multi-b-value diffusion-weighted imaging (DWI) were obtained. Machine learning by a non-linear support vector machine (SVM) was used to construct the best diagnostic algorithm for the prediction of local control and failure. The diagnostic accuracy was evaluated using a 9-fold cross-validation scheme, dividing patients into training and validation sets. Classification criteria for the division of local control and failure in nine training sets could be constructed with a mean sensitivity of 0.98, specificity of 0.91, positive predictive value (PPV) of 0.94, negative predictive value (NPV) of 0.97, and accuracy of 0.96. The nine validation data sets showed a mean sensitivity of 1.0, specificity of 0.82, PPV of 0.86, NPV of 1.0, and accuracy of 0.92. In conclusion, a machine-learning algorithm using various MR imaging-derived data can be helpful for the prediction of treatment outcomes in patients with sinonasal SCCs.
• Three-dimensional pseudo-continuous arterial spin-labeling using turbo-spin echo with pseudo-steady state readout: A comparison with other major readout methods

  Suzuko Aoike, Hiroyuki Sugimori, Noriyuki Fujima, Yuriko Suzuki, Yukie Shimizu, Akira Suwa, Kinya Ishizaka, Kohsuke Kudo

  Magnetic Resonance in Medical Sciences 18 2 170 - 177 2019年 [査読有り][通常論文]
   

  © 2018 Japanese Society for Magnetic Resonance in Medicine. We evaluated 3D pseudo-continuous arterial spin labeling (pCASL) using turbo spin echo with a pseudosteady- state (PSS) readout in comparison with the other major readout methods of 3D spiral and 2D echoplanar imaging (EPI). 3D-PSS produced cerebral blood flow (CBF) values well correlated to those of the 3D spiral readout. By visual evaluation, the image quality of 3D-PSS pCASL was superior to that of 2D-EPI. The 3D-PSS technique was suggested useful as pCASL readout.
• Integrating quantitative morphological and intratumoural textural characteristics in FDG-PET for the prediction of prognosis in pharynx squamous cell carcinoma patients.

  N Fujima, K Hirata, T Shiga, R Li, K Yasuda, R Onimaru, K Tsuchiya, S Kano, T Mizumachi, A Homma, K Kudo, H Shirato

  Clinical radiology 73 12 1059.e1-1059.e8  2018年12月 [査読有り][通常論文]
   

  AIM: To assess potential prognostic factors in pharynx squamous cell carcinoma (SCC) patients by quantitative morphological and intratumoural characteristics obtained by 2-[18F]-fluoro-2-deoxy-d-glucose positron-emission tomography/computed tomography (FDG-PET/CT). MATERIALS AND METHODS: The cases of 54 patients with pharynx SCC who underwent chemoradiation therapy were analysed retrospectively. Using their FDG-PET data, the quantitative morphological and intratumoural characteristics of 14 parameters were calculated. The progression-free survival (PFS) and overall survival (OS) information was obtained from patient medical records. Univariate and multivariate analyses were performed to assess the 14 quantitative parameters as well as the T-stage, N-stage, and tumour location data for their relation to PFS and OS. When an independent predictor was suggested in the multivariate analysis, the parameter was further assessed using the Kaplan-Meier method. RESULTS: In the assessment of PFS, the univariate and multivariate analyses indicated the following as independent predictors: the texture parameter of homogeneity and the morphological parameter of sphericity. In the Kaplan-Meier analysis, the PFS rate was significantly improved in the patients who had both a higher value of homogeneity (p=0.01) and a higher value of sphericity (p=0.002). With the combined use of homogeneity and sphericity, the patients with different PFS rates could be divided more clearly. CONCLUSION: The quantitative parameters of homogeneity and sphericity obtained by FDG-PET can be useful for the prediction of the PFS of pharynx SCC patients, especially when used in combination.
• Estimation of the number of feeding arteries of spinal arteriovenous malformations by using three-dimensional digital subtraction angiography.

  Takamiya S, Osanai T, Seki T, Fujima N, Hida K, Asano T, Yamazaki K, Hamauchi S, Sasamori T, Ono K, Terasaka S, Houkin K

  European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society 28 4 842 - 848 2018年12月 [査読有り][通常論文]
   

  PURPOSE: Spinal angiography is the gold standard for evaluation or diagnosis of spinal arteriovenous malformations (AVMs). However, some feeding arteries might be overlooked when multiple feeders exist. This study aimed to retrospectively review cases of spinal intra-dural AVMs, which were identified by three-dimensional digital subtraction angiography (3D-DSA), and attempted to estimate the number of feeding arteries. METHODS: We retrospectively reviewed patients with spinal intra-dural AVMs who underwent 3D-DSA at Hokkaido University Hospital from January 2005 to December 2016. We selected 9 patients in whom we could obtain data of multi-planar reconstruction of 3D-DSA. We measured the computed tomography (CT) values of feeding arteries and draining veins. The CT values represented the averages of maximum CT values of 5 continuous axial slices. The ratio of the CT value of feeders to that of drainers (F/D ratio) was calculated. The correlation between the F/D ratio and the number of feeders was examined with Pearson's correlation coefficient. RESULTS: The average number of feeders was 2.3 (1-4), and the number of feeders was significantly positively correlated with the F/D ratio (r = 0.855, P = .003). CONCLUSIONS: We conclude that the number of feeding arteries of spinal intra-dural AVMs can be estimated by using the F/D ratio obtained from 3D-DSA. These slides can be retrieved under Electronic Supplementary Material.
• Semi-quantitative analysis of pre-treatment morphological and intratumoral characteristics using ¹⁸F-fluorodeoxyglucose positron-emission tomography as predictors of treatment outcome in nasal and paranasal squamous cell carcinoma

  Noriyuki Fujima, Kenji Hirata, Tohru Shiga, Koichi Yasuda, Rikiya Onimaru, Kazuhiko Tsuchiya, Satoshi Kano, Takatsugu Mizumachi, Akihiro Homma, Kohsuke Kudo, Hiroki Shirato

  Quantitative Imaging in Medicine and Surgery 8 8 788 - 795 2018年09月 [査読有り][通常論文]
   

  © Quantitative Imaging in Medicine and Surgery. All rights reserved. Background: To investigate the utility of quantitative morphological and intratumoral characteristics obtained by 18F-fluorodeoxyglucose positron-emission tomography/computed tomography (FDG-PET/CT) for the prediction of treatment outcome in patients with nasal or paranasal cavity squamous cell carcinoma (SCC). Methods: Twenty-four patients with nasal or paranasal cavity SCC who received curative non-surgical therapy (a combination of super-selective arterial cisplatin infusion and radiotherapy) were retrospectively analyzed. From pre-treatment FDG-PET data, a total of 13 parameters of quantitative morphological characteristics (tumor volume, surface area and sphericity), intratumoral characteristics (the maximum and mean standard uptake value, three intratumoral histogram and four textural parameters) and total lesion glycolysis (TLG) were respectively calculated. Information regarding the treatment outcome was determined from the histological diagnosis or clinical follow-up. Each of the 13 quantitative parameters as well as T- and N-stage was assessed for its relation to treatment outcome of local control or failure. Results: In univariate analysis, significant differences in surface area and sphericity between the local control and failure groups were observed. The receiver operating characteristic (ROC) curve analysis showed that sphericity had the highest accuracy of 0.88. In the multivariate analysis, sphericity was revealed as an independent predictor of the local control or failure. Conclusions: The quantitative parameters of sphericity are useful to predict the treatment outcome in patients with nasal or paranasal SCC.
• Electrocardiogram-triggered angiography non-contrast enhanced (TRANCE) imaging to assess access route prior to diagnostic cerebral angiography.

  Osanai T, Kazumata K, Kobayashi S, Fujima N, Kurisu K, Shimoda Y, Houkin K

  World neurosurgery 119 237 - 241 2018年08月 [査読有り][通常論文]
   

  BACKGROUND: Electrocardiogram (ECG)-triggered angiography non-contrast-enhanced (TRANCE) imaging is useful for investigating peripheral vessel diseases; however, its efficacy for access route assessment in cerebral angiography has yet to be reported. Therefore we aimed to evaluate the efficacy of TRANCE imaging in the assessment of the access route before diagnostic subtraction angiography for cerebral vascular disorders. METHODS: TRANCE imaging was performed in all patients undergoing catheter angiography for disease diagnosis at our institute between April 2014 and March 2015. This study included 31 patients (14 men, 17 women) and investigated potential changes in the planned puncture site before and during the procedure (including the reason for the change) as our main outcome. RESULTS: TRANCE was successfully conducted in all of the patients recruited. TRANCE images led to an alteration in the approach vessel for 5 cases. The mean procedure time for angiography was <60 minutes. The median total number of catheters and guidewires used during catheter angiography was 1 (range: 1-3) and 1 (range: 1-2), respectively. There were no catheter angiography-related complications. CONCLUSIONS: TRANCE imaging before diagnostic angiography is useful because it allows detailed assessment of the access route. This practice may reduce procedure time, thus resulting in fewer complications.
• Utility of a Hybrid IVIM-DKI Model to Predict the Development of Distant Metastasis in Head and Neck Squamous Cell Carcinoma Patients.

  Noriyuki Fujima, Tomohiro Sakashita, Akihiro Homma, Daisuke Yoshida, Kohsuke Kudo, Hiroki Shirato

  Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 17 1 21 - 27 2018年01月10日 [査読有り][通常論文]
   

  PURPOSE: To evaluate the diagnostic power of hybrid intravoxel incoherent motion (IVIM)-diffusion kurtosis imaging (DKI) model parameters in pretreatment for the prediction of future distant metastasis in head and neck squamous cell carcinoma (HNSCC) patients. MATERIALS AND METHODS: We retrospectively evaluated 49 HNSCC patients who underwent curative chemoradiation therapy. Diffusion-weighted image (DWI) acquired by single-shot spin-echo echo-planar imaging with 12 b-values (0-2000) was performed in all patients before any treatment. We calculated the IVIM-DKI parameters and the conventional apparent diffusion coefficient (ADC) in the ROI placed on the primary lesion. The presence of future distant metastasis was determined by histological findings or clinical follow-up. RESULTS: A univariate analysis revealed significant differences between the patients with distant metastasis and those without in slow diffusion coefficient (D) and kurtosis value (K). Highest diagnostic accuracy was obtained by the D value. In addition, a multivariate analysis revealed that the D value was an independent predictor of future distant metastasis. CONCLUSION: The D and K values obtained by this hybrid IVIM-DKI model can be one of the diagnostic tools for the prediction of future distant metastasis in HNSCC patients.
• Acceleration of ASL-based time-resolved MR angiography by acquisition of control and labeled images in the same shot (ACTRESS)

  Yuriko Suzuki, Noriyuki Fujima, Tetsuo Ogino, James Alastair Meakin, Akira Suwa, Hiroyuki Sugimori, Marc Van Cauteren, Matthias J. P. van Osch

  MAGNETIC RESONANCE IN MEDICINE 79 1 224 - 233 2018年01月 [査読有り][通常論文]
   

  PurposeNoncontrast 4D-MR-angiography (MRA) using arterial spin labeling (ASL) is beneficial because high spatial and temporal resolution can be achieved. However, ASL requires acquisition of labeled and control images for each phase. The purpose of this study is to present a new accelerated 4D-MRA approach that requires only a single control acquisition, achieving similar image quality in approximately half the scan time. MethodsIn a multi-phase Look-Locker sequence, the first phase was used as the control image and the labeling pulse was applied before the second phase. By acquiring the control and labeled images within a single Look-Locker cycle, 4D-MRA was generated in nearly half the scan time of conventional ASL. However, this approach potentially could be more sensitive to off-resonance and magnetization transfer (MT) effects. To counter this, careful optimizations of the labeling pulse were performed by Bloch simulations. In in-vivo studies arterial visualization was compared between the new and conventional ASL approaches. ResultsOptimization of the labeling pulse successfully minimized off-resonance effects. Qualitative assessment showed that residual MT effects did not degrade visualization of the peripheral arteries. ConclusionThis study demonstrated that the proposed approach achieved similar image quality as conventional ASL-MRA approaches in just over half the scan time. Magn Reson Med 79:224-233, 2018. (c) 2017 International Society for Magnetic Resonance in Medicine.
• Noninvasive electrical conductivity measurement by MRI: a test of its validity and the electrical conductivity characteristics of glioma.

  Khin Khin Tha, Ulrich Katscher, Shigeru Yamaguchi, Christian Stehning, Shunsuke Terasaka, Noriyuki Fujima, Kohsuke Kudo, Ken Kazumata, Toru Yamamoto, Marc Van Cauteren, Hiroki Shirato

  European radiology 28 1 348 - 355 2018年01月 [査読有り][通常論文]
   

  OBJECTIVES: This study noninvasively examined the electrical conductivity (σ) characteristics of diffuse gliomas using MRI and tested its validity. METHODS: MRI including a 3D steady-state free precession (3D SSFP) sequence was performed on 30 glioma patients. The σ maps were reconstructed from the phase images of the 3D SSFP sequence. The σ histogram metrics were extracted and compared among the contrast-enhanced (CET) and noncontrast-enhanced tumour components (NCET) and normal brain parenchyma (NP). Difference in tumour σ histogram metrics among tumour grades and correlation of σ metrics with tumour grades were tested. Validity of σ measurement using this technique was tested by correlating the mean tumour σ values measured using MRI with those measured ex vivo using a dielectric probe. RESULTS: Several σ histogram metrics of CET and NCET of diffuse gliomas were significantly higher than NP (Bonferroni-corrected p ≤ .045). The maximum σ of NCET showed a moderate positive correlation with tumour grade (r = .571, Bonferroni-corrected p = .018). The mean tumour σ measured using MRI showed a moderate positive correlation with the σ measured ex vivo (r = .518, p = .040). CONCLUSIONS: Tissue σ can be evaluated using MRI, incorporation of which may better characterise diffuse gliomas. KEY POINTS: • This study tested the validity of noninvasive electrical conductivity measurements by MRI. • This study also evaluated the electrical conductivity characteristics of diffuse glioma. • Gliomas have higher electrical conductivity values than the normal brain parenchyma. • Noninvasive electrical conductivity measurement can be helpful for better characterisation of glioma.
• Fast acceleration of ASL-based time-resolved magnetic resonance angiography by acquisition of control and labeled images in the same shot (fast ACTRESS): An optimization study

  Hiroyuki Sugimori, Noriyuki Fujima, Yuriko Suzuki, Hiroyuki Hamaguchi, Kinya Ishizaka, Kohsuke Kudo

  MAGNETIC RESONANCE IMAGING 43 136 - 143 2017年11月 [査読有り][通常論文]
   

  Purpose: To establish an optimized sequence design for fast acceleration of arterial spin labeling (ASL)-based time-resolved magnetic resonance angiography (MRA) by acquisition of control and labeled images in the same shot (fast ACTRESS) and a scan time of <1 min, for the evaluation of intracranial vessels. Materials and methods: Ten healthy volunteers with no unilateral symptomatic arterial stenosis, who underwent 3-tesla MRI, were investigated. Imaging parameters for the fast ACTRESS sequence were set with an acquisition time of 45 s. During post-processing, the first phase in the multi-phase readout, which was defined as the control image, was subtracted from each of the other phases. Thus, four-dimensional (4D)-MRA images of each phase were obtained. The maximum intensity projection was used for the reconstruction of 4D-MRA images and time-to-signal intensity curves (TIC) obtained for each vessel. The area under the curve (AUC), peak time, and maximum signal intensity were obtained from TIC. The different labeling types were broadly divided into six groups: L1, L2, L3, L4, L5, and L6 according to the actual number of labeling pulse. Results: A total of 5040 regions of interest were evaluated. The peak SI of L3, except for those in the A2 segment of the anterior cerebral artery, was significantly higher than that of L5. However, there were no significant differences between L4 and L5. Although the AUCs of L3 and L4 for anterior circulation were relatively higher than that of the other subgroups, the AUC of L3 was significantly higher than that of L4. Conclusion: The fast ACTRESS was optimized and indicated that the labeling type of 13 was the most appropriate for the well visualization of intracranial arteries. The fast ACTRESS sequence was useful to acquire well-delineated images of intracranial vessels in 1 min. (C) 2017 Elsevier Inc. All rights reserved.
• Serial Arterial Spin Labeling May Be Useful in Assessing the Therapeutic Course of Cerebral Venous Thrombosis: Case Reports

  Sho Furuya, Masahito Kawabori, Noriyuki Fujima, Kikutaro Tokairin, Shuho Goto, Motoyuki Iwasaki, Yoshimasa Niiya, Shoji Mabuchi

  NEUROLOGIA MEDICO-CHIRURGICA 57 10 557 - 561 2017年10月 [査読有り][通常論文]
   

  We report two cases of cerebral venous thrombosis (CVT) which serial arterial spin labeling (ASL) was useful in evaluating the clinical course of the disease. A 48-year-old female presented with acute seizure, and was diagnosed as transverse-sigmoid sinus thrombosis. ASL imaging revealed low signal intensity in the right temporal lobe, suggesting the decreased perfusion by elevated venous pressure. Soon after the treatment, while the development of venous collateral has not fully observed by magnetic resonance (MR) angiography, low ASL signal within the right temporal lobe have shown remarkable improvement. A 65-year-old female presented with vomiting and subsequent seizure was diagnosed as superior sagittal sinus thrombosis. The low ASL signal within the right frontal lobe seen in the acute stage improved to the normal level by the course of time, before the good collateral can be seen by MR angiography. This is the first report to assess the sequential change of the cerebral perfusion of CVT by ASL, and ASL may provide additional useful information in combination with conventional modalities.
• Osteoradionecrosis of the hyoid bone after intra-arterial chemoradiotherapy for oropharyngeal cancer: MR imaging findings

  Hiromitsu Hatakeyama, Noriyuki Fujima, Kazuhiko Tsuchiya, Kenji Mizoguchi, Takatsugu Mizumachi, Tomohiro Sakashita, Satoshi Kano, Akihiro Homma, Satoshi Fukuda

  CANCER IMAGING 17 2017年07月 [査読有り][通常論文]
   

  Background: Osteoradionecrosis (ORN) of the hyoid bone sometimes induces severe front neck infection and can cause laryngeal stenosis and carotid rupture. Although ORN of the hyoid bone is known to be a complication of chemoradiotherapy for head and neck cancer, there has been no basis for its evaluation. Our purpose is to present the clinical and MR imaging features of ORN of the hyoid bone. Methods: The study group comprised patients with advanced oropharyngeal cancer treated with targeted intra-arterial cisplatin infusion with concomitant radiotherapy. ORN of the hyoid bone was identified on the basis of decreased signal intensity of the bone marrow on T1WI images. Signal intensity on T2WI images was used to distinguish between inflammation and fibrosis. Results: A total of 39 pre-treatment MR images and follow-up MR images were reviewed. ORN of the hyoid bone were detected in 30% of patients after treatment, with 23% of them showing inflammation and 7.7% fibrosis. Two patients developed severe neck infection and received antibiotics and underwent surgical intervention by tracheostomy and resection of the hyoid bone. Conclusion: Our MR imaging study showed that ORN of the hyoid bone is not particularly rare in patients with oropharyngeal cancer treated with chemoradiotherapy. Clinicians should evaluate images carefully to prevent the development of severe complication due to infection associated with ORN of the hyoid bone.
• Osteoradionecrosis of the hyoid bone after intra-arterial chemoradiotherapy for oropharyngeal cancer: MR imaging findings.

  Hatakeyama H, Fujima N, Tsuchiya K, Mizoguchi K, Mizumachi T, Sakashita T, Kano S, Homma A, Fukuda S

  Cancer imaging : the official publication of the International Cancer Imaging Society 17 1 22 - 22 2017年07月 [査読有り][通常論文]
   

  BACKGROUND: Osteoradionecrosis (ORN) of the hyoid bone sometimes induces severe front neck infection and can cause laryngeal stenosis and carotid rupture. Although ORN of the hyoid bone is known to be a complication of chemoradiotherapy for head and neck cancer, there has been no basis for its evaluation. Our purpose is to present the clinical and MR imaging features of ORN of the hyoid bone. METHODS: The study group comprised patients with advanced oropharyngeal cancer treated with targeted intra-arterial cisplatin infusion with concomitant radiotherapy. ORN of the hyoid bone was identified on the basis of decreased signal intensity of the bone marrow on T1WI images. Signal intensity on T2WI images was used to distinguish between inflammation and fibrosis. RESULTS: A total of 39 pre-treatment MR images and follow-up MR images were reviewed. ORN of the hyoid bone were detected in 30% of patients after treatment, with 23% of them showing inflammation and 7.7% fibrosis. Two patients developed severe neck infection and received antibiotics and underwent surgical intervention by tracheostomy and resection of the hyoid bone. CONCLUSION: Our MR imaging study showed that ORN of the hyoid bone is not particularly rare in patients with oropharyngeal cancer treated with chemoradiotherapy. Clinicians should evaluate images carefully to prevent the development of severe complication due to infection associated with ORN of the hyoid bone.
• Non-invasive prediction of the tumor growth rate using advanced diffusion models in head and neck squamous cell carcinoma patients

  Noriyuki Fujima, Tomohiro Sakashita, Akihiro Homma, Taisuke Harada, Yukie Shimizu, Khin Khin Tha, Kohsuke Kudo, Hiroki Shirato

  ONCOTARGET 8 20 33631 - 33643 2017年05月 [査読有り][通常論文]
   

  We assessed parameters of advanced diffusion weighted imaging (DWI) models for the prediction of the tumor growth rate in 55 head and neck squamous cell carcinoma (HNSCC) patients. The DWI acquisition used single-shot spin-echo echo-planar imaging with 12 b-values (0-2000). We calculated 14 DWI parameters using mono-exponential, bi-exponential, tri-exponential, stretched exponential and diffusion kurtosis imaging models. We directly measured the tumor growth rate from two sets of different-date imaging data. We divided the patients into a discovery group (n = 40) and validation group (n = 15) based on their MR acquisition dates. In the discovery group, we performed univariate and multivariate regression analyses to establish the multiple regression equation for the prediction of the tumor growth rate using diffusion parameters. The equation obtained with the discovery group was applied to the validation group for the confirmation of the equation's accuracy. After the univariate and multivariate regression analyses in the discovery-group patients, the estimated tumor growth rate equation was established by using the significant parameters of intermediate diffusion coefficient D-2 and slow diffusion coefficient D-3 obtained by the tri-exponential model. The discovery group's correlation coefficient between the estimated and directly measured tumor growth rates was 0.74. In the validation group, the correlation coefficient (r = 0.66) and intra-class correlation coefficient (0.65) between the estimated and directly measured tumor growth rates were respectively good. In conclusion, advanced DWI model parameters can be a predictor for determining HNSCC patients' tumor growth rate.
• Residual tumour detection in post-treatment granulation tissue by using advanced diffusion models in head and neck squamous cell carcinoma patients

  Noriyuki Fujima, Daisuke Yoshida, Tomohiro Sakashita, Akihiro Homma, Kohsuke Kudo, Hiroki Shirato

  EUROPEAN JOURNAL OF RADIOLOGY 90 14 - 19 2017年05月 [査読有り][通常論文]
   

  Purpose: To evaluate the detectability of the residual tumour in post-treatment granulation tissue using parameters obtained with an advanced diffusion model in patients with head and neck squamous cell carcinoma (HNSCC) treated by chemoradiation therapy. Materials and methods: We retrospectively evaluated 23 patients with HNSCC after the full course of chemoradiation therapy. The diffusion-weighted image (DWI) acquisition used single-shot spin-echo echo-planar imaging with 11 b-values (0-1000). We calculated 10 DWI parameters using a monoexponential model, a bi-exponential model, a stretched exponential model (SEM), a diffusion kurtosis imaging (DKI) model and a statistical diffusion model (SDM) in the region of interest (ROI) placed on the post-treatment granulation tissue. The presence of residual tumour was determined by histological findings or clinical follow-up. Results: Among the 23 patients, seven patients were revealed to have residual tumour. The univariate analysis revealed significant differences in six parameters between the patients with and without residual tumour. From the receiver operating characteristic curve analysis, the highest area under curve was detected in the center of the Gaussian distribution of diffusion coefficient (D-s) obtained by the SDM. The multivariate analysis revealed that the D-s and diffusion heterogeneity (alpha) obtained by the SEM were predictors for the presence of residual tumour. Conclusion: DWI parameters obtained by advanced fitting models will be one of the diagnostic tools for the detection of residual tumour. (C) 2017 Elsevier B.V. All rights reserved.
• Prediction of the treatment outcome using intravoxel incoherent motion and diffusional kurtosis imaging in nasal or sinonasal squamous cell carcinoma patients

  Noriyuki Fujima, Daisuke Yoshida, Tomohiro Sakashita, Akihiro Homma, Akiko Tsukahara, Yukie Shimizu, Khin Khin Tha, Kohsuke Kudo, Hiroki Shirato

  EUROPEAN RADIOLOGY 27 3 956 - 965 2017年03月 [査読有り][通常論文]
   

  To evaluate the diagnostic value of intravoxel incoherent motion (IVIM) and diffusional kurtosis imaging (DKI) parameters in nasal or sinonasal squamous cell carcinoma (SCC) patients to determine local control/failure. Twenty-eight patients were evaluated. MR acquisition used single-shot spin-echo EPI with 12 b-values. Quantitative parameters (mean value, 25th, 50th and 75th percentiles) of IVIM (perfusion fraction f, pseudo-diffusion coefficient D*, and true-diffusion coefficient D), DKI (kurtosis value K, kurtosis corrected diffusion coefficient D-k) and apparent diffusion coefficient (ADC) were calculated. Parameter values at both the pretreatment and early-treatment period, and the percentage change between these two periods were obtained. Multivariate logistic regression analysis: the percentage changes of D (mean, 25th, 50th, 75th), K (mean, 50th, 75th), Dk (mean, 25th, 50th), and ADC (mean, 25th, 50th) were predictors of local control. ROC curve analysis: the parameter with the highest accuracy = the percentage change of D value with the histogram 25th percentile (0.93 diagnostic accuracy). Multivariate Cox regression analyses: the percentage changes of D (mean, 25th, 50th), K (mean, 50th, 75th), Dk (mean, 25th, 50th) and ADC (mean, 25th, 50th) are predictors. IVIM and DKI parameters, especially the D-value's histogram 25th percentile, are useful for predicting local control. Noninvasive assessment of treatment outcome in SCC patients was achieved using IVIM/DKI. Several IVIM and DKI parameters can predict the local control. Especially, the D-value's histogram 25th percentile has high diagnostic accuracy.
• Advanced diffusion models in head and neck squamous cell carcinoma patients: Goodness of fit, relationships among diffusion parameters and comparison with dynamic contrast-enhanced perfusion

  Noriyuki Fujima, Tomohiro Sakashita, Akihiro Homma, Yukie Shimizu, Atsushi Yoshida, Taisuke Harada, Khin Khin Tha, Kohsuke Kudo, Hiroki Shirato

  MAGNETIC RESONANCE IMAGING 36 16 - 23 2017年02月 [査読有り][通常論文]
   

  Purpose: We assessed advanced fitting models of diffusion weighted imaging (DWI) in head/neck squamous cell carcinoma (HNSCC) patients to determine the best goodness of fit and correlations among diffusion parameters. We compared these results with those of dynamic contrast-enhanced (DCE) perfusion parameters. Materials and methods: We retrospectively evaluated 32 HNSCC patients (12 sinonasal, 20 pharynx/oral cavity). The DWI acquisition used single-shot spin-echo echo-planar imaging (EPI) with 12 b-values (0 - 2000). We calculated 14 DWI parameters using mono-exponential, bi-exponential, and tri-exponential models, stretched exponential model (SEM) and diffusion kurtosis imaging (DKI) models. We compared each model's goodness of fit using the residual sum of squares (RSS), Akaike Information Criterion (AIC) and Bayesian information criterion (BIC) value. We determined the correlation between each pair of DWI parameters and between each DWI parameter and DCE perfusion parameter. Results: The tri-exponential fit's RSS, AIC and BIC values were significantly smaller than those for bi-exponential fit. The RSS, AIC and BIC values of the SEM fit and DKI fit were significantly smaller than mono-exponential model. Significant correlations were observed in 30 pairs (sinonasal cavity) and 31 (sinonasal cavity group) among 91 DWI parameter combinations. Significant correlations were also observed in nine pairs (both sinonasal cavity and pharynx/oral cavity group) among 64 DWI/DCE perfusion parameter pairs, in particular, high positive correlations between the tri-exponential model's intermediate diffusion fraction (f(2)) and the volume of the extracellular extravascular space per unit volume of tissue (v(e)) were observed in both patient groups. Conclusion: We identified several correlations between DWI parameters by advanced fitting models and correlations between DWI and DCE parameters. These will help determine HNSCC patients' detailed tissue structures. (C) 2016 Elsevier Inc. All rights reserved.
• Synergistic Interactions Between Direct and Indirect Bypasses in Combined Procedures: The Significance of Indirect Bypasses in Moyamoya Disease

  Haruto Uchino, Jae-Hoon Kim, Noriyuki Fujima, Ken Kazumata, Masaki Ito, Naoki Nakayama, Satoshi Kuroda, Kiyohiro Houkin

  NEUROSURGERY 80 2 201 - 208 2017年02月 [査読有り][通常論文]
   

  BACKGROUND: Whether additional indirect bypasses effectively contribute to revascular-ization in combined procedures remains unclear in patients with moyamoya disease. OBJECTIVE: To evaluate the longitudinal changes associated with combined procedures while following up pediatric and adult patients long term and to assess whether any other clinical factors or hemodynamic parameters affected these changes to determine an optimal surgical strategy. METHODS: We studied 58 hemispheres in 43 adults and 39 hemispheres in 26 children who underwent combined revascularization for moyamoya disease. To evaluate bypass development, we assessed the sizes of the superficial temporal artery and middle meningeal artery using magnetic resonance angiography. Multivariate analysis determined the effects of multiple variables on bypass development. RESULTS: Indirect bypass ( middle meningeal artery) development occurred in 95% and 78% of the pediatric and adult hemispheres, respectively. Of these, dual development of direct and indirect bypasses occurred in 54% of the pediatric hemispheres and in 47% of the adult hemispheres. Reciprocal superficial temporal artery regression occurred in 28% of the hemispheres during the transition from the postoperative acute phase to the chronic phase during indirect bypass development. Good indirect bypass development was associated with adult hemispheres at Suzuki stage 4 or greater ( odds ratio, 7.4; 95% confidence interval, 1.4-39.4; P = .02). Disease onset type and preoperative hemodynamic parameters were not considered predictors for the development of surgical revascularization. CONCLUSION: Simultaneous direct and indirect bypass development was most frequently observed, regardless of patient age and hemodynamic status. Applying indirect bypass as an adjunct to direct bypass could maximize revascularization in adults and children.
• Comparison of Different Post-Processing Algorithms for Dynamic Susceptibility Contrast Perfusion Imaging of Cerebral Gliomas

  Kohsuke Kudo, Ikuko Uwano, Toshinori Hirai, Ryuji Murakami, Hideo Nakamura, Noriyuki Fujima, Fumio Yamashita, Jonathan Goodwin, Satomi Higuchi, Makoto Sasaki

  MAGNETIC RESONANCE IN MEDICAL SCIENCES 16 2 129 - 136 2017年 [査読有り][通常論文]
   

  Purpose: The purpose of the present study was to compare different software algorithms for processing DSC perfusion images of cerebral tumors with respect to i) the relative CBV (rCBV) calculated, ii) the cutoff value for discriminating low- and high-grade gliomas, and iii) the diagnostic performance for differentiating these tumors. Methods: Following approval of institutional review board, informed consent was obtained from all patients. Thirty-five patients with primary glioma (grade II, 9; grade III, 8; and grade IV, 18 patients) were included. DSC perfusion imaging was performed with 3-Tesla MRI scanner. CBV maps were generated by using 11 different algorithms of four commercially available software and one academic program. rCBV of each tumor compared to normal white matter was calculated by ROI measurements. Differences in rCBV value were compared between algorithms for each tumor grade. Receiver operator characteristics analysis was conducted for the evaluation of diagnostic performance of different algorithms for differentiating between different grades. Results: Several algorithms showed significant differences in rCBV, especially for grade IV tumors. When differentiating between low- (II) and high-grade (III/IV) tumors, the area under the ROC curve (Az) was similar (range 0.85-0.87), and there were no significant differences in Az between any pair of algorithms. In contrast, the optimal cutoff values varied between algorithms (range 4.18-6.53). Conclusions: rCBV values of tumor and cutoff values for discriminating low- and high-grade gliomas differed between software packages, suggesting that optimal software-specific cutoff values should be used for diagnosis of high-grade gliomas.
• Glucose Metabolism and Its Complicated Relationship with Tumor Growth and Perfusion in Head and Neck Squamous Cell Carcinoma

  Noriyuki Fujima, Tomohiro Sakashita, Akihiro Homma, Kenji Hirata, Tohru Shiga, Kohsuke Kudo, Hiroki Shirato

  PLOS ONE 11 11 e0166236  2016年11月 [査読有り][通常論文]
   

  Objective To determine the relationship between tumor glucose metabolism and tumor blood flow (TBF) in head and neck squamous cell carcinoma (HNSCC). Methods We retrospectively analyzed 57 HNSCC patients. Tumor glucose metabolism was assessed by maximum and mean standardized uptake values (SUVmax and SUVmean) obtained by 18 F-fluorodeoxyglucose positron-emission tomography. TBF values were obtained by arterial spin labeling with 3-tesla MRI. The correlations between both SUVs and TBF were assessed in the total series and among patients divided by T-stage (T1-T3 and T4 groups) and tumor location (pharynx/oral cavity and sinonasal cavity groups). Pearson's correlation coefficients were calculated for significant correlations. Results Significant correlations were detected: a negative correlation in the advanced T-stage group (TBF and SUV max: r, -0.61, SUVmean: r, -0.62), a positive correlation in the non-advanced T-stage pharynx/oral cavity group (TBF and SUVmax: r, 0.70, SUVmean: r, 0.73), a negative correlation in the advanced T-stage pharynx/oral cavity group (TBF and SUVmax: r, -0.62, SUVmean: r, -0.65), and a negative correlation in the advanced Tstage sinonasal cavity group (TBF and SUVmax: r, -0.61, SUVmean: r, -0.65). Conclusion Significant correlations between glucose uptake and TBF in HNSCC were revealed by the division of T-stage and tumor location.
• Effectiveness of superselective intra-arterial chemoradiotherapy targeting retropharyngeal lymph node metastasis

  Takayoshi Suzuki, Tomohiro Sakashita, Akihiro Homma, Hiromitsu Hatakeyama, Satoshi Kano, Takatsugu Mizumachi, Daisuke Yoshida, Noriyuki Fujima, Rikiya Onimaru, Kazuhiko Tsuchiya, Koichi Yasuda, Hiroki Shirato, Fumiyuki Suzuki, Satoshi Fukuda

  EUROPEAN ARCHIVES OF OTO-RHINO-LARYNGOLOGY 273 10 3331 - 3336 2016年10月 [査読有り][通常論文]
   

  We sought to evaluate the efficacy and feasibility of superselective intra-arterial infusion of high-dose cisplatin with concomitant radiotherapy (hereafter RADPLAT) for head and neck squamous cell cancer (hereafter HNSCC) patients with retropharyngeal lymph node (hereafter RPLN) metastasis. A retrospective case series review was conducted at University medical center in Japan. Ten HNSCC patients with RPLN metastasis treated by RADPLAT were analyzed. The ascending pharyngeal artery was targeted for the treatment of RPLN metastasis in 9 patients. The median total dose of cisplatin was 26.6 mg/m(2) (mean 31.5 mg/m(2), range 11.7-87.9 mg/m(2)). In the remaining patient, the RPLN was supplied by the ascending palatine artery. As grade 3 and 4 adverse effects, leukopenia was observed in three, mucositis in four and nausea in one patient. No neurological complications were observed in any patients. Metastatic RPLNs were evaluated as a complete response in all patients. There was no recurrence of RPLN metastasis in any patients. Four patients remain alive without any evidence of disease and six patients died of disease. The 5-year overall survival rate was 50 %. We have shown that superselective intra-arterial cisplatin infusion for RPLNs was a feasible and effective approach for HNSCC patients with RPLN metastasis.
• Utility of noncontrast-enhanced time-resolved four-dimensional MR angiography with a vessel-selective technique for intracranial arteriovenous malformations

  Noriyuki Fujima, Toshiya Osanai, Yukie Shimizu, Atsushi Yoshida, Taisuke Harada, Naoki Nakayama, Kohsuke Kudo, Kiyohiro Houkin, Hiroki Shirato

  JOURNAL OF MAGNETIC RESONANCE IMAGING 44 4 834 - 845 2016年10月 [査読有り][通常論文]
   

  PurposeTo evaluate the utility of a vessel-selective four-dimensional (4D) magnetic resonance angiography (MRA) technique for the evaluation of intracranial arteriovenous malformations (AVMs). Materials and MethodsTwelve AVM patients were evaluated retrospectively. Time-of-flight (TOF) MRA, nonvessel-selective 4D-MRA (NS-4D-MRA), and vessel-selective 4D-MRA (VS-4D-MRA) were performed using a 3T MR unit in all patients, and used to identify feeding arteries and draining veins and measure nidus size. The diagnostic accuracy of the three techniques was compared using digital subtraction angiography (DSA). If a multifeeder was observed, the percentage of blood flow of each feeding artery to the entire nidus was evaluated and compared to the DSA findings using the error value, defined as the degree of overestimation of the blood flow. All imaging findings were assessed by two neuroradiologists. ResultsIn both raters, the detectability of feeding arteries by VS-4D-MRA (12 and 11 patients) was significantly higher than those of TOF-MRA (7 and 6 patients) and NS-4D-MRA (8 and 7 patients) (P < 0.016). The detectability of drainer veins by TOF-MRA (10 and 10 patients) was significantly higher than that of VS-4D-MRA (7 and 6 patients). In the percentage of the blood flow of each feed artery to the entire nidus, the DSA findings (error value; 27.15.7) indicated overestimations of the blood flow compared to the VS-4D-MRA (error value; 7.1 +/- 3.9) (P < 0.001). ConclusionVS-4D-MRA was shown to be a useful technique for the evaluation of intracranial AVMs, especially for detecting feed arteries and estimating details of the nidus structure. J. MAGN. RESON. IMAGING 2016;44:834-845.
• Usefulness of Pseudocontinuous Arterial Spin-Labeling for the Assessment of Patients with Head and Neck Squamous Cell Carcinoma by Measuring Tumor Blood Flow in the Pretreatment and Early Treatment Period.

  N Fujima, D Yoshida, T Sakashita, A Homma, A Tsukahara, K K Tha, K Kudo, H Shirato

  AJNR. American journal of neuroradiology 37 2 342 - 8 2016年02月 [査読有り][通常論文]
   

  BACKGROUND AND PURPOSE: For the assessment of the treatment response in non-surgical treatment, tumor blood flow provides the functional information of the tumor which is different from the morphological information such as tumor volume. The purpose of this study was to evaluate the diagnostic value of tumor blood flow values obtained by pseudocontinuous arterial spin-labeling in patients with head and neck squamous cell carcinoma. MATERIALS AND METHODS: Forty-one patients with head and neck squamous cell carcinoma were evaluated by using pseudocontinuous arterial spin-labeling. Quantitative tumor blood flow was calculated at the pretreatment and the early treatment periods in all the patients, and the percentage change of tumor blood flow between the two was calculated. At the early treatment period, based on their tumor volume reduction rate, we divided the patients into stable disease and partial response groups for a subgroup analysis. The local control or failure was confirmed either by histopathology or by radiologic evaluation within the follow-up. RESULTS: Pretreatment tumor blood flow in patients in the failure group was significantly lower than that in patients in the local control group. In the subgroup analysis of patients with stable disease, the percentage change of tumor blood flow was significantly larger (due to the tumor blood flow increase from pretreatment value) in the local control group than in the failure group. In addition, in patients with a partial response, the percentage change of tumor blood flow was significantly smaller (due to the tumor blood flow decrease from the pretreatment value) in the local control group than in the failure group. The accuracy for determination of the local control group or the failure group in pretreatment tumor blood flow was 0.83 and that in the combination use of the percentage change of tumor blood flow and tumor volume in the early treatment period was 0.93. CONCLUSIONS: Tumor blood flow obtained by pseudocontinuous arterial spin-labeling can be useful for the determination of local control. The combined use of the percentage change of tumor blood flow and tumor volume had particularly high diagnostic accuracy.
• Synergistic Interactions Between Direct and Indirect Bypasses in Combined Procedures: The Significance of Indirect Bypasses in Moyamoya Disease.

  Uchino H, Kim JH, Fujima N, Kazumata K, Ito M, Nakayama N, Kuroda S, Houkin K

  Neurosurgery 2016年01月 [査読有り][通常論文]
  
• Evaluation of diagnostic accuracy in CT perfusion analysis in moyamoya disease

  Takashi Ohno, Kohsuke Kudo, Greg Zaharchuk, Noriyuki Fujima, Hiroki Shirato

  JAPANESE JOURNAL OF RADIOLOGY 34 1 28 - 34 2016年01月 [査読有り][通常論文]
   

  The purpose of the present study was to determine optimal threshold of vascular pixel elimination (VPE) for CT perfusion (CTP) and to assess diagnostic accuracy of CTP by comparing with xenon enhanced CT (XeCT) in moyamoya disease. Twenty-three patients underwent XeCT and CTP. Cerebral blood flow (CBF) images were generated for XeCT and CTP using nine types of software. Region of interest (ROI) measurement was performed on XeCT-CBF and CTP-CBF. Linear regression analysis was performed between XeCT-CBF and CTP-CBF in all software, without and with VPE. The Pearson correlation coefficient was calculated, and an optimal threshold was determined based on maximum correlation coefficients. Correlation coefficients at various VPE thresholds including data of no-VPE were compared with each other. The maximum correlation coefficient at the optimal threshold was also compared. Optimal thresholds varied among software types (0.8-2.2 and 7-14 ml/100 g in relative and absolute VPE, respectively). There were significant differences between correlation coefficients at a range of VPE thresholds compared to no-VPE in most software types. There were significant differences in maximum correlation coefficient at optimal threshold among various software types. Optimal threshold of VPE for CTP could be determined and diagnostic accuracy of CTP varied among software types in moyamoya disease.
• Evaluation of cerebral blood flow using multi-phase pseudo continuous arterial spin labeling at 3-tesla

  Hiroyuki Sugimori, Noriyuki Fujima, Yuriko Suzuki, Hiroyuki Hamaguchi, Motomichi Sakata, Kohsuke Kudo

  MAGNETIC RESONANCE IMAGING 33 10 1338 - 1344 2015年12月 [査読有り][通常論文]
   

  Purpose: Arterial spin labeling (ASL) methods have been widely used for evaluation of cerebral blood flow (CBF) by magnetic resonance imaging. However, ASL methods require setting of the post labeling delay (PLD) time for obtaining images. As the hemodynamic status cannot be estimated in each patient, the resultant quantitative values of blood flow may not be accurate. The multi-phase pseudo continuous arterial spin labeling (pCASL) method can be used to obtain images at various time-points. The purpose of this study was to create the transit-time maps for correcting the delayed blood flow and evaluate CBF using the transit-time maps obtained by the multi-phase pCASL method. Materials and Methods: Twelve patients who underwent both 3.0-tesla magnetic resonance imaging (MRI) and single photon emission computed tomography with iodine-123-N-isopropyl-p-iodoamphetamine (123I-IMP) were investigated. This study was approved by the institutional review board of our institution. MRI acquisitions included PLD time-fixed (1525 ms) and multi-phase pCASL sequences. The transit-time maps were calculated from multi-phase pCASL images by software. The transit-time maps were applied to PLD-fixed pCASL images pixel by pixel, for calculating the CBF value corrected for peak blood transit time. Regions of interest were drawn on the brain. IMP-CBF, ASL-CBF (default and corrected) and transit time were measured for each segment. Results: Twelve patients and 264 segments were investigated. The mean IMP-CBF, ASL-CBF (default, corrected) and transit time were 28.4, 23.0, 29.6, [ml/min/100 g] and 1977.5 [ms], respectively. There were no significant differences between IMP-CBF and ASL-CBF (corrected). Conclusion: CBF values can be corrected by using the transit-time maps obtained using the multi-phase pCASL method. (C) 2015 Elsevier Inc. All rights reserved.
• Diagnostic value of tumor blood flow and its histogram analysis obtained with pCASL to differentiate sinonasal malignant lymphoma from squamous cell carcinoma

  Noriyuki Fujima, Hiroyuki Kameda, Akiko Tsukahara, Daisuke Yoshida, Tomohiro Sakashita, Akihiro Homma, Khin Khin Tha, Kohsuke Kudo, Hiroki Shirato

  EUROPEAN JOURNAL OF RADIOLOGY 84 11 2187 - 2193 2015年11月 [査読有り][通常論文]
   

  Objectives: To investigate the diagnostic value of tumor blood flow (TBF) obtained with pseudocontinuous arterial spin labeling (pCASL) for the differentiation of squamous cell carcinoma (SCC) and malignant lymphoma (ML) in the nasal or sinonasal cavity. Methods: Thirty-three patients with SCC and 6 patients with ML in the nasal or sinonasal cavity were retrospectively analyzed. Quantitative TBF values were obtained using whole-tumor region of interest (ROI) from pCASL data. The histogram analysis of TBF values within the tumor ROI was also performed by calculating the coefficient of variation (CV), kurtosis, and skewness. The mean TBF value, histogram CV, kurtosis and skewness of the patients with SCC were compared with those of the ML patients. The diagnostic accuracy to differentiate SCC from ML was also calculated by receiver operating characteristic (ROC) curve analysis. In addition, multiple logistic regression models were also performed to determine their independent predictive value, and diagnostic accuracy with the combined use of these parameters. Results: Between the SCC and ML groups, significant differences were observed in mean TBF, CV, and kurtosis, but not in skewness. In ROC curve analysis, the diagnostic accuracy values for the differentiation of SCC from ML in mean TBF, CV, and kurtosis were all 0.87, respectively. Multiple logistic regression models revealed TBF and CV were respectively independent predictive value. With the combination of these parameters, the diagnostic accuracy was elevated to 0.97. Conclusions: The TBF value and its histogram analysis obtained with pCASL can help differentiate SCC and ML. (C) 2015 Elsevier Ireland Ltd. All rights reserved.
• A novel application of four-dimensional magnetic resonance angiography using an arterial spin labeling technique for noninvasive diagnosis of Moyamoya disease

  Haruto Uchino, Masaki Ito, Noriyuki Fujima, Ken Kazumata, Kazuyoshi Yamazaki, Naoki Nakayama, Satoshi Kuroda, Kiyohiro Houkin

  CLINICAL NEUROLOGY AND NEUROSURGERY 137 105 - 111 2015年10月 [査読有り][通常論文]
   

  Background: Noncontrast-enhanced time-resolved four-dimensional magnetic resonance angiography using an arterial spin labeling technique (ASL-4D MRA) is emerging as a next generation angiography for the management of neurovascular diseases. This study evaluated the feasibility of ASL-4D MRA for the diagnosis of Moyamoya disease (MMD) and MMD staging by using digital subtraction angiography (DSA) and time-of-flight MRA (TOF MRA) as current standards. Methods: Eleven consecutive non-operated patients who underwent DSA for the diagnosis of MMD were recruited. Two independent observers evaluated the three tests. The data were analyzed for inter-observer and inter-modality agreements on MMD stage. Nine of 22 hemispheres underwent surgical revascularization and ASL-4D MRA was repeated postoperatively. Results: Time-resolved inflow of blood through the cerebral vessels, including moyamoya vessels, was visualized in all the 22 non-operated hemispheres. MMD stages assessed by DSA and ASL-4D MRA were completely matched in 18 hemispheres, with a significant positive correlation between these modalities (r=0.93, P<0.001). Inter-observer agreement with ASL-4D MRA (K=0.91 +/- 0.04, P<0.001) and inter-modality agreement between ASL-4D MRA and DSA (K = 0.93 +/- 0.04, P<0.001) were both excellent. MMD stages assessed by ASL-4D MRA have also a significant positive correlation with those assessed by TOF MRA (r=0.68, P=0.004). Repeated ASL-4D MRA clearly demonstrated the bypassed arteries and changes in the dynamic flow patterns of cerebral arteries in all the nine hemispheres after surgical revascularization. Of these, postoperative focal hyperperfusion was detected by single photon emission tomography in 7 hemispheres. In five of the seven hemispheres (71%) with postoperative hyperperfusion, ASL-4D MRA demonstrated focal hyperintense signals in the bypassed arteries, although TOF MRA did not. Conclusions: Noninvasive ASL-4D MRA is feasible for the diagnosis of MMD staging. This next generation angiography may be useful for monitoring disease evolution and treatment response in cerebral arteries after revascularization surgery in MMD. (C) 2015 Elsevier B.V. All rights reserved.
• [What radiologists require in head CT].

  Noriyuki Fujima

  Nihon Hoshasen Gijutsu Gakkai zasshi 71 5 449 - 55 2015年05月
• Measurement of Tumor Blood Flow in Head and Neck Squamous Cell Carcinoma by Pseudo-Continuous Arterial Spin Labeling: Comparison With Dynamic Contrast-Enhanced MRI

  Noriyuki Fujima, Kohsuke Kudo, Akiko Tsukahara, Daisuke Yoshida, Tomohiro Sakashita, Akihiro Homma, Khin Khin Tha, Hiroki Shirato

  JOURNAL OF MAGNETIC RESONANCE IMAGING 41 4 983 - + 2015年04月 [査読有り][通常論文]
   

  PurposeTo investigate the feasibility of tumor blood flow (TBF) measurement in head and neck squamous cell carcinoma (HNSCC) using pseudo-continuous arterial spin labeling (pCASL) in a comparison with dynamic contrast-enhanced (DCE) perfusion. Materials and MethodsWe prospectively scanned 18 patients with HNSCC using 3T magnetic resonance imaging (MRI) with both pCASL and DCE perfusion. Quantitative TBF value in the whole-tumor region of interest (ROI), and regional TBF in the ROIs of the central and peripheral areas in the tumor were respectively measured. Relative TBF value in the whole-tumor ROI was also calculated. We determined the correlation and agreement between each measured TBF by pCASL and DCE perfusion using Pearson's correlation coefficients, intraclass correlation coefficients (ICC), and Bland-Altman analysis. ResultsIn the whole-tumor ROIs, significant correlation was observed between the absolute TBF values (r=0.72, P<0.01), with an ICC of 0.72; moreover, higher correlation was observed in the relative TBF (r=0.79). The correlation was higher in the peripheral ROI (r=0.70) than the central ROI (r=0.65), with an ICC of 0.62 and 0.54, respectively. Bland-Altman plots revealed the underestimation of TBF by pCASL in central ROIs. ConclusionTBF measurement by pCASL was feasible in patients with HNSCC. J. Magn. Reson. Imaging 2015;41:983-991. (c) 2014 Wiley Periodicals, Inc.
• Measurement of tumor blood flow in head and neck squamous cell carcinoma by pseudo-continuous arterial spin labeling: comparison with dynamic contrast-enhanced MRI.

  Noriyuki Fujima, Kohsuke Kudo, Akiko Tsukahara, Daisuke Yoshida, Tomohiro Sakashita, Akihiro Homma, Khin Khin Tha, Hiroki Shirato

  Journal of magnetic resonance imaging : JMRI 41 4 983 - 91 2015年04月 [査読有り][通常論文]
   

  PURPOSE: To investigate the feasibility of tumor blood flow (TBF) measurement in head and neck squamous cell carcinoma (HNSCC) using pseudo-continuous arterial spin labeling (pCASL) in a comparison with dynamic contrast-enhanced (DCE) perfusion. MATERIALS AND METHODS: We prospectively scanned 18 patients with HNSCC using 3T magnetic resonance imaging (MRI) with both pCASL and DCE perfusion. Quantitative TBF value in the whole-tumor region of interest (ROI), and regional TBF in the ROIs of the central and peripheral areas in the tumor were respectively measured. Relative TBF value in the whole-tumor ROI was also calculated. We determined the correlation and agreement between each measured TBF by pCASL and DCE perfusion using Pearson's correlation coefficients, intraclass correlation coefficients (ICC), and Bland-Altman analysis. RESULTS: In the whole-tumor ROIs, significant correlation was observed between the absolute TBF values (r = 0.72, P < 0.01), with an ICC of 0.72; moreover, higher correlation was observed in the relative TBF (r = 0.79). The correlation was higher in the peripheral ROI (r = 0.70) than the central ROI (r = 0.65), with an ICC of 0.62 and 0.54, respectively. Bland-Altman plots revealed the underestimation of TBF by pCASL in central ROIs. CONCLUSION: TBF measurement by pCASL was feasible in patients with HNSCC. J. Magn. Reson. Imaging 2015;41:1-1. © 2014 Wiley Periodicals, Inc.
• Utility of 4D-MRA to Measure Blood Flow Velocity in Cerebral Major Arteries

  Abumiya Takeo, Fujima Noriyuki, Kudo Kohsuke, Ishi Yukitomo, Gekka Masayuki, Shichinohe Hideo, Kazumata Ken, Nakayama Naoki, Houkin Kiyohiro

  STROKE 46 2015年02月 [査読有り][通常論文]
  
• Differentiation of squamous cell carcinoma and inverted papilloma using non-invasive MR perfusion imaging.

  N Fujima, Y Nakamaru, T Sakashita, A Homma, A Tsukahara, K Kudo, H Shirato

  Dento maxillo facial radiology 44 9 20150074 - 20150074 2015年 [査読有り][通常論文]
   

  OBJECTIVES: To investigate the diagnostic value of tumour blood flow (TBF) obtained with pseudocontinuous arterial spin labelling for the differentiation of squamous cell carcinoma (SCC) and inverted papilloma (IP) in the nasal or sinonasal cavity. METHODS: We retrospectively analysed the cases of 33 patients with SCC and 8 patients with IP in the nasal or sinonasal cavity. Pseudocontinuous arterial spin labelling scanning was performed for all patients using a 3.0-T MR unit. Quantitative TBF values were measured by two neuroradiologists by respectively delineating the whole-tumour regions of interest, and the mean of them was determined as TBF value in each patient. Additionally, the presence of imaging findings of convoluted cerebriform pattern (CCP) on MR T2 weighted images was determined in all patients. As a subgroup analysis, patients with IP were divided into aggressive and non-aggressive IPs depending on their progression range. First, an intraclass correlation coefficient (ICC) of TBF values between two neuroradiologists was determined. Next, a statistical comparison of the TBF value by a Mann-Whitney U test between the patients with SCC and IP was performed. Additionally, the comparison by an ANOVA with a post hoc test of Tukey's method among the SCC, non-aggressive IP and aggressive IP groups was also performed. If significance was observed, the diagnostic accuracy to differentiate SCCs from IPs was calculated. Diagnostic accuracy by CCP findings alone and by the combination of CCP findings and TBF were also assessed. RESULTS: The ICC of TBF values between two neuroradiologists was 0.82. The mean TBF values in the patients with SCC, all patients with IP, those with aggressive IP and those with non-aggressive IP were 141.2 ± 33.1, 77.8 ± 31.5, 109.4 ± 16.7 and 58.8 ± 19.9 ml 100 g⁻¹ min⁻¹, respectively. A significant difference was observed between SCC and IP (p < 0.001), SCC and non-aggressive IP (p < 0.01) and non-aggressive IP and aggressive IP (p < 0.01). The diagnostic accuracy values obtained with receiver operating characteristic curve analysis for the differentiation of SCC from IP and for SCC from non-aggressive IP were 0.90 and 0.92, respectively. The diagnostic accuracy was elevated (0.95 from 0.88) by adding the TBF value to CCP findings. CONCLUSIONS: The pseudocontinuous arterial spin labelling technique can be a useful non-invasive diagnostic tool to differentiate SCC from IP in nasal or sinonasal cavity.
• Intravoxel incoherent motion diffusion-weighted imaging in head and neck squamous cell carcinoma: Assessment of perfusion-related parameters compared to dynamic contrast-enhanced MRI

  Noriyuki Fujima, Daisuke Yoshida, Tomohiro Sakashita, Akihiro Homma, Akiko Tsukahara, Khin Khin Tha, Kohsuke Kudo, Hiroki Shirato

  MAGNETIC RESONANCE IMAGING 32 10 1206 - 1213 2014年12月 [査読有り][通常論文]
   

  Purpose: To investigate the correlation between perfusion-related parameters obtained with intravoxel incoherent motion (IVIM) and classical perfusion parameters obtained with dynamic contrast-enhanced (DCE) magnetic resonance imaging in patients with head and neck squamous cell carcinoma (HNSCC), and to compare direct and asymptotic fitting, the pixel-by-pixel approach, and a region of interest (ROI)-based approach respectively for IVIM parameter calculation. Materials and methods: Seventeen patients with HNSCC were included in this retrospective study. All magnetic resonance (MR) scanning was performed using a 3 T MR unit. Acquisition of IVIM was performed using single-shot spin-echo echo-planar imaging with three orthogonal gradients with 12 b-values (0, 10, 20, 30, 50, 80, 100, 200, 400, 800, 1000, and 2000). Perfusion-related parameters of perfusion fraction 'f' and the pseudo-diffusion coefficient 'D*' were calculated from IVIM data by using least square fitting with the two fitting methods of direct and asymptotic fitting, respectively. DCE perfusion was performed in a total of 64 dynamic phases with a 3.2-s phase interval. The two-compartment exchange model was used for the quantification of tumor blood volume (TBV) and tumor blood flow (TBF). Each tumor was delineated with a polygonal ROI for the calculation of f, f center dot D* performed using both the pixel-by-pixel approach and the ROI-based approach. In the pixel-by-pixel approach, after fitting each pixel to obtain f, f center dot D* maps, the mean value in the delineated ROI on these maps was calculated. In the ROI-based approach, the mean value of signal intensity was calculated within the ROI for each b-value in IVIM images, and then fitting was performed using these values. Correlations between fin a total of four combinations (direct or asymptotic fitting and pixel-by-pixel or ROI-based approach) and TBV were respectively analyzed using Pearson's correlation coefficients. Correlations between f center dot D* and TBF were also similarly analyzed. Results: In all combinations of f and TBV, f center dot D* and TBF, there was a significant correlation. In the comparison of f and TBV, a moderate correlation was observed only between f obtained by direct fitting with the pixel-by-pixel approach, whereas a good correlation was observed in the comparisons using the other three combinations. In the comparison of f center dot D* and TBF, a good correlation was observed only with f center dot D* obtained by asymptotic fitting with the ROI-based approach. In contrast, moderate correlations were observed in the comparisons using the other three combinations. Conclusion: IVIM was found to be feasible for the analysis of perfusion-related parameters in patients with HNSCC. Especially, the combination of asymptotic fitting with the ROI-based approach was better correlated with DCE perfusion. (C) 2014 Elsevier Inc. All rights reserved.
• Improvement of the Diagnostic Accuracy of MRA with Subtraction Technique in Cerebral Vasospasm

  Akiyoshi Hamaguchi, Noriyuki Fujima, Daisuke Yoshida, Naoko Hamaguchi, Shuichi Kodera

  JOURNAL OF NEUROIMAGING 24 6 548 - 553 2014年11月 [査読有り][通常論文]
   

  PURPOSE Vasospasm has been considered the most severe acute complication after subarachnoid hemorrhage (SAH). MRA is not considered ideal for detecting cerebral vasospasm because of background including the hemorrhage. The aim of this study is to evaluate the efficacy of Subtraction MRA (SMRA) by comparing it to that of conventional MRA (CMRA) for diagnosis of cerebral vasospasm. METHODS Arteries were assigned to one of three categories based on the degree of MRA diagnostic quality of vasospasm (quality score): 0, bad ... 2, good. Furthermore each artery was assigned to one of four categories based on the degree of vasospasm severity (SV score): 0, no vasospasm ... 3, severe. The value of the difference between DSA-SV score and MRA-SV score was defined as the DIF score. CMRA and SMRA were compared for each arterial region with regard to quality score and DIF score. RESULTS The average CMRA and SMRA quality score were 1.46 and 1.79; the difference was statistically significant. The average CMRA and SMRA DIF score were 1.08 and.60; the difference was statistically significant. CONCLUSIONS Diagnosis of cerebral vasospasm is more accurate by SMRA than by CMRA. The advantages are its noninvasive nature and its ability to detect cerebral vasospasm.
• The incidence of late neck recurrence in N0 maxillary sinus squamous cell carcinomas after superselective intra-arterial chemoradiotherapy without prophylactic neck irradiation

  Tomohiro Sakashita, Akihiro Homma, Hiromitsu Hatakeyama, Satoshi Kano, Takatsugu Mizumachi, Jun Furusawa, Daisuke Yoshida, Noriyuki Fujima, Rikiya Onimaru, Kazuhiko Tsuchiya, Koichi Yasuda, Hiroki Shirato, Satoshi Fukuda

  EUROPEAN ARCHIVES OF OTO-RHINO-LARYNGOLOGY 271 10 2767 - 2770 2014年10月 [査読有り][通常論文]
   

  The efficacy of elective neck irradiation (ENI) for patients with N0 carcinoma of the maxillary sinus has been controversial. The purpose of our study was to investigate the incidence of late neck recurrence and the mortality rate from regional disease in patients with N0 maxillary sinus cancer after superselective cisplatin infusion and concomitant radiotherapy (RADPLAT) without ENI. We retrospectively analyzed 48 patients with N0 maxillary sinus cancer who underwent RADPLAT. Chemotherapy consisted of 100-120 mg/m(2) superselective intra-arterial cisplatin administered at a median rate of four times weekly. Concurrent radiation therapy was administered at a median dose of 65 Gy without ENI. Late neck recurrence was observed in 8.3 % (4/48). Three patients underwent salvage neck dissection and survived without any evidence of disease. The remaining patient did not undergo neck dissection due to coexistence with distant metastasis, and he died of regional disease. The mortality rate from regional disease was calculated to be 2 % (1/48). The incidence of late neck recurrence was not frequent, and the mortality rate from regional disease was low. Salvage neck dissection was considered to be feasible for patients with late neck recurrence. When definitive radiotherapy and concomitant chemotherapy are applied, it is considered that ENI is not required for cases of N0 maxillary sinus cancer.
• Arterial Spin Labeling to Determine Tumor Viability in Head and Neck Cancer Before and After Treatment

  Noriyuki Fujima, Kohsuke Kudo, Daisuke Yoshida, Akihiro Homma, Tomohiro Sakashita, Akiko Tsukahara, Khin Khin Tha, Yuri Zaitsu, Satoshi Terae, Hiroki Shirato

  JOURNAL OF MAGNETIC RESONANCE IMAGING 40 4 920 - 928 2014年10月 [査読有り][通常論文]
   

  Purpose: To evaluate the feasibility of arterial spin-labeling (ASL) in head and neck cancer for noninvasive measurement of tumor blood flow (TBF), by comparing 1) the TBF change before and after the treatment, and 2) posttreatment TBF and its reduction rate between residual and nonresidual tumors after treatment. Materials and Methods: Twenty-two patients with head and neck cancer were evaluated using ASL on 3.0-T magnetic resonance imaging (MRI) before and after nonsurgical treatment. A pulsed ASL sequence with Look-Locker readout was used to calculate quantitative TBF. TBF reduction rates between pre- and posttreatment values were also calculated. Residual tumors were confirmed when present with either histopathologically or clinical follow-up. Results: Pre- and posttreatment mean TBF values were 121.4 +/- 27.8 (standard deviation) and 24.9 +/- 14.9 mL/100g/min, respectively. Pre-and posttreatment TBF differed significantly. Posttreatment TBF was significantly higher in patients with residual tumors (five patients, 46.9 +/- 7.1 mL/100g/min) than in those without (17 patients, 18.4 +/- 9.2 mL/100g/min). The TBF reduction rate was significantly lower in patients with residual tumors (0.540.55 +/- 0.120.12) than in those without (0.85 +/- 0.06). Conclusion: ASL allows quantitative assessment of TBF in head and neck cancer. ASL may be useful for noninvasive assessment of tumor viability in head and neck cancer.
• Radiological images of keratocystoma: a rare tumor of the parotid gland.

  Hirata K, Fujima N, Mizumachi T, Bandarchi B, Roesler JM

  Acta radiologica short reports 3 8 2047981614549497 - 2047981614549497 2014年09月 [査読有り][通常論文]
   

  A 34-year-old man found a mildly tender preauricular mass. Ultrasonography revealed an anechoic mass in the superficial lobe of the parotid gland. Magnetic resonance imaging showed thin ring-like contrast enhancement and homogenously high intensity on T2-weighted images. The mass was resected due to its rapid growth. The cystic lesion contained keratine-like material and a stratified squamous epithelium without granular layers, which was consistent with keratocystoma.
• Prediction of the Attachment Site of Sinonasal Inverted Papillomas by Preoperative Imaging

  Yuji Nakamaru, Noriyuki Fujima, Dai Takagi, Akiko Tsukahara, Daisuke Yoshida, Satoshi Fukuda

  ANNALS OF OTOLOGY RHINOLOGY AND LARYNGOLOGY 123 7 468 - 474 2014年07月 [査読有り][通常論文]
   

  Objective: Accurate preoperative identification of the attachment site is the key to the successful surgical management of sinonasal inverted papillomas (IPs). This study investigated the value of preoperative imaging to identify the attachment sites of IPs. Methods: We analyzed 10 consecutive patients with pathologically proven IPs. Two radiologists predicted the attachment sites of IPs from computed tomography (CT), 3.0 Tesla magnetic resonance imaging (3.0T MRI), 1.5T MRI, and CT plus 3.0T MRI. The actual tumor attachment sites were confirmed via pathological examination of specimens and compared with the predicted sites. Results: Computed tomography showed the highest sensitivity (P < .0001), although both MRI formats showed greater specificity (P < .0001). The sensitivity of MRI plus CT was equal to that of CT and better than that of MRI (P <.0001), whereas its specificity was better than that of CT (P < .0001) and comparable to that of MRI. Prediction using 3.0T MRI appeared slightly superior to that using 1.5T MRI in terms of sensitivity and specificity, although the differences were not significant. Conclusion: Computed tomography and MRI had different features for prediction of sinonasal IP attachment sites. Preoperative CT plus MRI provided more useful information than CT or MRI alone.
• Salvage operations for patients with persistent or recurrent cancer of the maxillary sinus after superselective intra-arterial infusion of cisplatin with concurrent radiotherapy

  Tomohiro Sakashita, Akihiro Homma, Hiromitsu Hatakeyama, Satoshi Kano, Takatsugu Mizumachi, Jun Furusawa, Daisuke Yoshida, Noriyuki Fujima, Rikiya Onimaru, Kazuhiko Tsuchiya, Koichi Yasuda, Hiroki Shirato, Fumiyuki Suzuki, Satoshi Fukuda

  BRITISH JOURNAL OF ORAL & MAXILLOFACIAL SURGERY 52 4 323 - 328 2014年04月 [査読有り][通常論文]
   

  Our aim was to evaluate the feasibility of salvage operations for patients with persistent or recurrent cancer of the maxillary sinus after superselective intra-arterial infusion of cisplatin with concurrent radiotherapy. We retrospectively analysed the records of 61 patients with cancer of the maxillary sinus who were treated in this way. Chemotherapy comprised 100-120 mg/m(2) superselective intra-arterial infusions of cisplatin given a median of 4 times weekly (range 2-5). Concurrent radiotherapy was given in a median dose of 65 Gy (range 24-70 Gy). Persistent or recurrent cancer of the maxillary sinus was found in 17 patients, of whom 11 had salvage surgery. The disease was controlled in 8 of the 11, and 7 of the 11 survived with no evidence of disease. Their 5-year overall survival was 61%. Two of the 11 developed serious operative complications. Salvage surgery for patients with persistent or recurrent cancer of the maxillary sinus treated by superselective chemoradiotherapy is both safe and successful. Salvage surgery is a good option when this sort of persistent or recurrent cancer is followed up after the regimen of chemoradiotherapy described. (C) 2014 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
• Salvage operations for patients with persistent or recurrent cancer of the maxillary sinus after superselective intra-arterial infusion of cisplatin with concurrent radiotherapy

  Sakashita T, Homma A, Hatakeyama H, Kano S, Mizumachi T, Furusawa J, Yoshida D, Fujima N, Onimaru R, Tsuchiya K, Yasuda K, Shirato H, Suzuki F, Fukuda S

  Br J Oral Maxillofac Surg 52 4 323 - 8 2014年 [査読有り][通常論文]
  
• Isolated posterior fossa involvement in posterior reversible encephalopathy syndrome.

  Yukie Shimizu, Khin Khin Tha, Akihiro Iguchi, Yuko Cho, Atsushi Yoshida, Noriyuki Fujima, Akiko Tsukahara, Hiroki Shirato, Satoshi Terae

  The neuroradiology journal 26 5 514 - 9 2013年10月 [査読有り][通常論文]
   

  Posterior reversible encephalopathy syndrome (PRES) is characterized by reversible vasogenic edema affecting the subcortical white matter of bilateral occipital and parietal lobes. We describe a case of isolated posterior fossa involvement of PRES which occurred during remission induction chemotherapy for T-cell acute lymphoblastic leukemia. Both the brainstem and cerebellum were extensively involved, but the supratentorial structures were completely spared. The follow-up magnetic resonance images revealed reversibility of most lesions. The knowledge of atypical radiological features of PRES is essential for prompt diagnosis.
• Impaired integrity of the brain parenchyma in non-geriatric patients with major depressive disorder revealed by diffusion tensor imaging.

  Khin K Tha, Satoshi Terae, Shin Nakagawa, Takeshi Inoue, Nobuki Kitagawa, Yuki Kako, Yasuya Nakato, Kawser Akter Popy, Noriyuki Fujima, Yuri Zaitsu, Daisuke Yoshida, Yoichi M Ito, Tamaki Miyamoto, Tsukasa Koyama, Hiroki Shirato

  Psychiatry research 212 3 208 - 15 2013年06月30日 [査読有り][通常論文]
   

  Diffusion tensor imaging (DTI) is considered to be able to non-invasively quantify white matter integrity. This study aimed to use DTI to evaluate white matter integrity in non-geriatric patients with major depressive disorder (MDD) who were free of antidepressant medication. DTI was performed on 19 non-geriatric patients with MDD, free of antidepressant medication, and 19 age-matched healthy subjects. Voxel-based and histogram analyses were used to compare fractional anisotropy (FA) and mean diffusivity (MD) values between the two groups, using two-sample t tests. The abnormal DTI indices, if any, were tested for correlation with disease duration and severity, using Pearson product-moment correlation analysis. Voxel-based analysis showed clusters with FA decrease at the bilateral frontal white matter, anterior limbs of internal capsule, cerebellum, left putamen and right thalamus of the patients. Histogram analysis revealed lower peak position of FA histograms in the patients. FA values of the abnormal clusters and peak positions of FA histograms of the patients exhibited moderate correlation with disease duration and severity. These results suggest the implication of frontal-subcortical circuits and cerebellum in MDD, and the potential utility of FA in evaluation of brain parenchymal integrity.
• Impaired integrity of the brain parenchyma in non-geriatric patients with major depressive disorder revealed by diffusion tensor imaging

  Khin K. Tha, Satoshi Terae, Shin Nakagawa, Takeshi Inoue, Nobuki Kitagawa, Yuki Kako, Yasuya Nakato, Kawser Akter Popy, Noriyuki Fujima, Yuri Zaitsu, Daisuke Yoshida, Yoichi M. Ito, Tamaki Miyamoto, Tsukasa Koyama, Hiroki Shirato

  PSYCHIATRY RESEARCH-NEUROIMAGING 212 3 208 - 215 2013年06月 [査読有り][通常論文]
   

  Diffusion tensor imaging (DTI) is considered to be able to non-invasively quantify white matter integrity. This study aimed to use DTI to evaluate white matter integrity in non-geriatric patients with major depressive disorder (MDD) who were free of antidepressant medication. DTI was performed on 19 non-geriatric patients with MDD, free of antidepressant medication, and 19 age-matched healthy subjects. Voxel-based and histogram analyses were used to compare fractional anisotropy (FA) and mean diffusivity (MD) values between the two groups, using two-sample t tests. The abnormal DTI indices, if any, were tested for correlation with disease duration and severity, using Pearson product-moment correlation analysis. Voxel-based analysis showed clusters with FA decrease at the bilateral frontal white matter, anterior limbs of internal capsule, cerebellum, left putamen and right thalamus of the patients. Histogram analysis revealed lower peak position of FA histograms in the patients. FA values of the abnormal clusters and peak positions of FA histograms of the patients exhibited moderate correlation with disease duration and severity. These results suggest the implication of frontal-subcortical circuits and cerebellum in MDD, and the potential utility of FA in evaluation of brain parenchymal integrity. (C) 2012 Elsevier Ireland Ltd. All rights reserved.
• Evaluation of renal blood flow using multi-phase echo-planar magnetic resonance imaging and signal targeting with alternating radiofrequency (EPISTAR) in 3-T magnetic resonance imaging

  Hiroyuki Sugimori, Mitsuhiro Nakanishi, Noriyuki Fujima, Kinya Ishizaka, Suzuko Mito, Hiroyuki Hamaguchi, Motomichi Sakata

  Radiological Physics and Technology 6 1 86 - 91 2013年01月 [査読有り][通常論文]
   

  Most arterial spin labeling techniques apply the constant post-labeling delay time after the blood-labeling time point on the target artery. As the hemodynamic status cannot be estimated in each patient, quantitative values of the blood flow may not be accurate. To overcome this problem, we performed renal perfusion imaging of human kidneys using multi-phase echo-planar magnetic resonance imaging and signal targeting with an alternating radiofrequency (EPISTAR) sequence at 3-T magnetic resonance imaging. Multi-phase EPISTAR obtained 17 phases every 100 ms between 250 and 1850 ms from the arterial-labeling time point. The highest signal-intensity image obtained using multi-phase images was applied to renal blood flow (RBF) calculations. In five healthy volunteers, the mean cortical RBF was 286.6 ± 48.7 mL/100 g/min. This value was not significantly different from those in four previous studies. This technique was more useful than previous studies, in that multi-phase images could confirm the hemodynamic status on RBF calculations. © 2012 Japanese Society of Radiological Technology and Japan Society of Medical Physics.
• Detection of Brain Metastases by 3-Dimensional Magnetic Resonance Imaging at 3 T: Comparison Between T1-Weighted Volume Isotropic Turbo Spin Echo Acquisition and 3-Dimensional T1-Weighted Fluid-Attenuated Inversion Recovery Imaging

  Atsushi Yoshida, Khin Khin Tha, Noriyuki Fujima, Yuri Zaitsu, Daisuke Yoshida, Akiko Tsukahara, Shunsuke Onodera, Hiroki Shirato, Satoshi Terae

  JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY 37 1 84 - 90 2013年01月 [査読有り][通常論文]
   

  Objective: This study aimed to compare the diagnostic performance in the detection of brain metastases between contrast-enhanced T1-weighted volume isotropic turbo spin echo acquisition (T1-VISTA) and 3-dimensional T1-weighted fluid-attenuated inversion recovery (3D-T1-FLAIR) imaging at 3 T.Methods: Two neuroradiologists selected 129 true (metastases) and 70 false (vessels and artifacts) lesions on the contrast-enhanced T1-VISTA and 3D-T1-FLAIR images of 14 cancer patients with hyperintense brain lesions. Four blinded neuroradiologists distinguished between the true and false lesions, using a 5-point confidence rating scale. The receiver operating characteristic analysis was performed to compare the diagnostic performance. Contrast-to-noise ratio of the true lesions was also compared between the 2 sequences by using paired t tests.Results: For lesions less than 3 mm, the area under curve and sensitivity achieved by T1-VISTA imaging were significantly greater than 3D-T1-FLAIR imaging. The contrast-to-noise ratio was also significantly greater with T1-VISTA imaging.Conclusions: The contrast-enhanced T1-VISTA imaging is better suited than 3D-T1-FLAIR imaging, for detection of small metastases.
• (11)C-Methionine positron emission tomography may monitor the activity of encephalitis.

  Kenji Hirata, Tohru Shiga, Noriyuki Fujima, Osamu Manabe, Reiko Usui, Yuji Kuge, Nagara Tamaki

  Acta radiologica (Stockholm, Sweden : 1987) 53 10 1155 - 7 2012年12月01日 [査読有り][通常論文]
   

  Encephalitis is generally diagnosed by clinical symptoms, cerebrospinal fluid examination, and imaging studies including CT, magnetic resonance imaging (MRI), and perfusion single photon emission tomography (SPECT). However, the role of positron emission tomography (PET) in diagnosis of encephalitis remains unclear. A 49-year-old woman presenting with coma and elevated inflammatory reaction was diagnosed as having encephalitis according to slow activity on electroencephalogram, broad cortical lesion in MR fluid attenuated inversion recovery image, and increased blood flow demonstrated by SPECT. PET revealed increased accumulation of (11)C-methionine (MET) in the affected brain tissues. After the symptom had improved 2 months later, the accumulation of MET as well as the abnormal findings of MR imaging and SPECT was normalized. This case indicated that MET PET may monitor the activity of encephalitis.
• Platinum concentration in sentinel lymph nodes after preoperative intra-arterial cisplatin chemotherapy targeting primary tongue cancer

  Tomohiro Sakashita, Akihiro Homma, Nobuhiko Oridate, Seigo Suzuki, Hiromitsu Hatakeyama, Satoshi Kano, Takatsugu Mizumachi, Daisuke Yoshida, Noriyuki Fujima, Satoshi Fukuda

  ACTA OTO-LARYNGOLOGICA 132 10 1121 - 1125 2012年10月 [査読有り][通常論文]
   

  Conclusion: We conclude that intra-arterially injected cisplatin passed via lymph flow into sentinel nodes (SNs) as the platinum concentration in the SNs was higher than that in the non-sentinel nodes (NSNs). It is possible that preoperative intra-arterial chemotherapy targeting primary cancer also has a therapeutic effect on subclinical metastatic SNs. Objectives: Intra-arterial chemoradiotherapy has been reported to be effective against not only primary tumors but also nodal metastases. We considered the hypothesis that intra-arterially injected cisplatin passed via lymph flow into regional nodes. This study aimed to investigate intra-arterially injected cisplatin distribution to regional nodes by comparing platinum concentrations in SNs and NSNs. Methods: Five patients with T1-2 N0 tongue cancer were treated with preoperative intra-arterial chemotherapy (cisplatin, 100 mg/m(2)) targeting primary cancer. Partial glossectomy together with SN biopsy and elective neck dissection were performed 2 weeks after intra-arterial chemotherapy. Platinum concentrations in the lymph nodes were measured using a Zeeman atomic absorption spectrometer. Results: Thirteen SNs were harvested together with eight NSNs from the areas adjacent to the SNs. Platinum concentrations were then measured, revealing a significant difference in platinum concentration between the SNs and the NSNs (mean +/- SD, 0.682 +/- 0.246 mu g/g vs 0.506 +/- 0.274 mu g/g; p = 0.049).
• Mapping of cerebral oxygen extraction fraction changes with susceptibility-weighted phase imaging.

  Yuri Zaitsu, Kohsuke Kudo, Satoshi Terae, Rie Yazu, Kinya Ishizaka, Noriyuki Fujima, Khin K Tha, E Mark Haacke, Makoto Sasaki, Hiroki Shirato

  Radiology 261 3 930 - 6 2011年12月 [査読有り][通常論文]
   

  PURPOSE: To develop a map to detect changes in oxygen extraction fraction (OEF) utilizing susceptibility-weighted (SW) phase images and to correlate such changes in OEF with those in cerebral blood flow (CBF). MATERIALS AND METHODS: The study protocol was approved by the institutional review board, and written informed consent was obtained from all subjects. Eight healthy volunteers (mean age ± standard deviation, 29.8 years ± 4.6) were included in the study. Subjects were evaluated by using SW imaging, and the change in OEF was calculated by subtracting the image at baseline from one of the images obtained during six different conditions, including two at resting state, three different types of respiratory challenges, and one drug challenge with acetazolamide. Arterial spin labeling was carried out to measure CBF, while SW imaging was used to generate maps of change in OEF in response to a given condition. Statistical tests included one-way analysis of variance and Dunnett multiple comparisons to compare among the six conditions the magnitude of change from baseline for both OEF and CBF, by using the OEF change at resting state (resting 1) as the control. RESULTS: Hyperventilation caused a statistically significant decrease in CBF (-29.3%, P < .001) and an increase in OEF (+5.2%, P < .001) compared with the control, resting 1 (+2.2%, -0.7%, respectively). Acetazolamide caused a significant increase in CBF (+39.7%, P < .001) and a decrease in OEF (-3.4%, P = .040). Carbogen also induced a CBF increase (+16.2%); however, the change was not significant (P = .090), even though OEF decreased significantly (-4.2%, P = .003). Oxygen administration resulted in a significant CBF decrease (-27.2%, P < .001), whereas OEF showed no significant difference (-0.6%, P > .99). CONCLUSION: Maps of changes in OEF generated from SW phase images revealed changes in OEF corresponding to anticipated changes in CBF induced by various conditions; SW phase imaging might, in the future, be applied to evaluate cerebrovascular and other cerebral disorders in which changes in oxygen metabolism are important for planning therapeutic strategies.
• RELATIONSHIP BETWEEN DISEASED LUNG TISSUES ON COMPUTED TOMOGRAPHY AND MOTION OF FIDUCIAL MARKER NEAR LUNG CANCER

  Yuya Onodera, Noriko Nishoka, Koichi Yasuda, Noriyuki Fujima, Mylin Torres, Tamotsu Kamishima, Noriko Ooyama, Rikiya Onimaru, Satoshi Terae, Satoshi Ooizumi, Masaharu Nishimura, Hiroki Shirato

  INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 79 5 1408 - 1413 2011年04月 [査読有り][通常論文]
   

  Purpose: For lung cancer patients with poor pulmonary function because of emphysema or fibrosis, it is important to predict the amplitude of internal tumor motion to minimize the irradiation of the functioning lung tissue before undergoing stereotactic body radiotherapy. Methods and Materials: Two board-certified diagnostic radiologists independently assessed the degree of pulmonary emphysema and fibrosis on computed tomography scans in 71 patients with peripheral lung tumors before real-time tumor-tracking radiotherapy. The relationships between the computed tomography findings of the lung parenchyma and the motion of the fiducial marker near the lung tumor were investigated. Of the 71 patients, 30 had normal pulmonary function, and 29 had obstructive pulmonary dysfunction (forced expiratory volume in 1 s/forced vital capacity ratio of < 70%), 6 patients had constrictive dysfunction (percentage of vital capacity < 80%), and 16 had mixed dysfunction. Results: The upper region was associated with smaller tumor motion, as expected (p = .0004), and the presence of fibrosis (p = .088) and pleural tumor contact (p = .086) were weakly associated with tumor motion. The presence of fibrotic changes in the lung tissue was associated with smaller tumor motion in the upper region (p <.05) but not in the lower region. The findings of emphysema and pulmonary function tests were not associated with tumor motion. Conclusion: Tumors in the upper lung region with fibrotic changes have smaller motion than those in the upper region of the lungs without fibrotic changes. The tumor motion in the lower lung region was not significantly different between patients with and without lung fibrosis. Emphysema was not associated with the amplitude of tumor motion. (C) 2011 Elsevier Inc.
• Relationship between diseased lung tissues on computed tomography and motion of fiducial marker near lung cancer.

  Onodera Y, Nishioka N, Yasuda K, Fujima N, Torres M, Kamishima T, Ooyama N, Onimaru R, Terae S, Ooizumi S, Nishimura M, Shirato H

  Int J Radiat Oncol Biol Phys 79 5 1408 - 13 2011年 [査読有り][通常論文]
  
• Non-invasive measurement of oxygen saturation in the spinal vein using SWI: Quantitative evaluation under conditions of physiological and caffeine load

  Noriyuki Fujima, Kohsuke Kudo, Satoshi Terae, Kinya Ishizaka, Rie Yazu, Yuri Zaitsu, Khin Khin Tha, Daisuke Yoshida, Akiko Tsukahara, Mark E. Haacke, Makoto Sasaki, Hiroki Shirato

  NEUROIMAGE 54 1 344 - 349 2011年01月 [査読有り][通常論文]
   

  Susceptibility-weighted imaging (SWI) has been used for quantitative and non-invasive measurement of blood oxygen saturation in the brain. In this study, we used SWI for quantitative measurement of oxygen saturation in the spinal vein to look for physiological- or caffeine-induced changes in venous oxygenation. SWI measurements were obtained for 5 healthy volunteers using 1.5-T MR units, under 1) 3 kinds of physiological load (breath holding, Bh; hyperventilation, Hv; and inspiration of highly concentrated oxygen. Ox) and 2) caffeine load. Oxygen saturation in the anterior spinal vein (ASV) was calculated. We evaluated changes in oxygen saturation induced by physiological load. We also evaluated the time-course of oxygen saturation after caffeine intake. For the physiological load measurements, the average oxygen saturation for the 5 subjects was significantly lower in Hv (0.75) and significantly higher in Bh (0.84) when compared with control (0.80). There was no significant difference between Ox (0.81) and control. Oxygen saturation gradually decreased after caffeine intake. The average values of oxygen saturation were 0.79 (0 min), 0.76 (20 min), 0.74 (40 min), and 0.73 (60 min), respectively. We demonstrated a significant difference in oxygen saturation at 40 and 60 min after caffeine intake when compared with 0 min. In conclusion, we demonstrated the feasibility of using SWI for non-invasive measurement of oxygen saturation in the spinal vein. We showed changes in oxygen saturation under physiological as well as caffeine load and suggest that this method is a useful tool for the clinical evaluation of spinal cord oxygenation. (C) 2010 Elsevier Inc. All rights reserved.
• Susceptibility-weighted imaging and magnetic resonance angiography during migraine attack: a case report.

  Yusuke Shimoda, Kohsuke Kudo, Satoshi Kuroda, Yuri Zaitsu, Nobuyuki Fujima, Satoshi Terae, Makoto Sasaki, Kiyohiro Houkin

  Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 10 1 49 - 52 2011年 [査読有り][通常論文]
   

  We performed magnetic resonance angiography (MRA) and susceptibility-weighted imaging (SWI) to observe cerebral changes during a migraine attack in a 28-year-old man. MRA revealed regional arterial spasm, and findings of SWI were consistent with decreased blood flow and/or venous dilatation. Because these noninvasive techniques can be performed repeatedly at short intervals, they can be useful for evaluating hemodynamic changes during and after migraine attacks.
• Detection of Active Plaques in Multiple Sclerosis using Susceptibility-weighted Imaging: Comparison with Gadolinium-enhanced MR Imaging

  Masako Suzuki, Kohsuke Kudo, Makoto Sasaki, Satoshi Takahashi, Jyunko Takahashi, Noriyuki Fujima, Ikuko Uwano, Hisashi Yonezawa, Masako Kudo, Hikoaki Fukaura, Naoki Ishizuka, Yasuo Terayama

  MAGNETIC RESONANCE IN MEDICAL SCIENCES 10 3 185 - 192 2011年 [査読有り][通常論文]
   

  Purpose: Susceptibility-weighted (SW) imaging is a magnetic resonance (MR) imaging technique reported effective in visualizing multiple sclerosis (MS) plaques, but its capacity to distinguish active plaques remains unclear. We evaluated active plaque detection by SW compared with contrast-enhanced MR imaging. Methods: We prospectively examined 11 patients using a 3-tesla scanner. Two neuroradiologists independently evaluated signal changes of plaques and accompanying low signal rims in 74 plaques on various SW images (magnitude, phase, and minimum intensity projection [minIP]), and on contrast-enhanced T(1)-weighted images (T(1)WI). We correlated signal alterations on various SW images and contrast enhancement on T(1)WI using Fisher's exact test and calculated sensitivity and specificity for predicting gadolinium enhancement. Results: Only changes in plaque signal on SW magnitude images correlated significantly with contrast enhancement of the plaques (P = 0.008), and high signal intensity had 0.556 sensitivity and 0.787 specificity for predicting contrast-enhanced plaques. Furthermore, plaques with rims of low signal showed sensitivity of 0.296 and specificity of 0.957. Conclusions: Susceptibility-weighted magnitude, but not phase or minIP, images can predict MS plaques with contrast enhancement with high specificity.
• Microstructural white matter abnormalities of multiple system atrophy: in vivo topographic illustration by using diffusion-tensor MR imaging.

  Khin K Tha, Satoshi Terae, Ichiro Yabe, Tamaki Miyamoto, Hiroyuki Soma, Yuri Zaitsu, Noriyuki Fujima, Kohsuke Kudo, Hidenao Sasaki, Hiroki Shirato

  Radiology 255 2 563 - 9 2010年05月 [査読有り][通常論文]
   

  PURPOSE: To determine whether diffusion-tensor (DT) imaging can demonstrate microstructural white matter abnormalities of multiple system atrophy (MSA) and to correlate these imaging findings with clinical signs and symptoms. MATERIALS AND METHODS: Institutional review board approval and written informed consent were obtained. DT imaging was performed in 16 patients with MSA with predominant cerebellar symptoms (MSA-C) (mean age, 60.0 years + or - 5.1 [standard deviation]; range, 51-69 years) and 16 age-matched healthy subjects. Fractional anisotropy (FA) and mean diffusivity (MD) were compared voxel-by-voxel between the two groups by using a two-sample t test. Overlap maps were created to illustrate areas with FA and MD alterations. Correlation between DT imaging indexes and Barthel index score, scale for assessment and rating of ataxia (SARA) score, severity of orthostatic hypotension, age of disease onset, and disease duration was tested by using Spearman rank or Pearson product-moment correlation analysis. T2-weighted and proton density-weighted images of the patients were visually assessed. RESULTS: Widespread areas of FA reduction and MD elevation were observed in supra- and infratentorial white matter structures in patients with MSA (P < .05, false discovery rate corrected). Significant correlation (P < .01) between DT imaging indexes and Barthel index score, SARA score, severity of orthostatic hypotension, and disease duration was observed for multiple areas with FA and/or MD alterations. T2-weighted and proton density-weighted images showed no significant abnormality in supratentorial white matter. CONCLUSION: DT imaging may help identify the microstructural white matter abnormalities of MSA-C. DT imaging may be useful for severity assessment of MSA-C.
• Spinal Arteriovenous Malformation: Evaluation of Change in Venous Oxygenation with Susceptibility-weighted MR Imaging after Treatment

  Noriyuki Fujima, Kohsuke Kudo, Satoshi Terae, Kazutoshi Hida, Kinya Ishizaka, Yuri Zaitsu, Takeshi Asano, Daisuke Yoshida, Khin Khin Tha, E. Mark Haacke, Makoto Sasaki, Hiroki Shirato

  RADIOLOGY 254 3 891 - 899 2010年03月 [査読有り][通常論文]
   

  Purpose: To evaluate the efficacy of susceptibility-weighted (SW) magnetic resonance (MR) imaging for the assessment of the post-treatment change in oxygen saturation in the draining vein in patients with spinal arteriovenous malformation (AVM). Materials and Methods: The study protocol was approved by the institutional review board, and written informed consent was obtained from all subjects. SW imaging was performed in 11 patients with spinal AVM before and after surgical or endovascular treatment. Eleven healthy subjects were included as a control group. A four-grade response scale was used for the visual assessment of the anterior spinal vein (ASV). For quantitative analysis, the phase value of the ASV was measured and oxygen saturation was calculated. Nonparametric multigroup comparison for visual assessment and one-way analysis of variance for quantitative measurement of oxygen saturation were used as statistical tests for comparison among three groups (pretreatment patients, posttreatment patients, and control subjects). Results: Complete shunt occlusion in all patients was confirmed by using conventional angiography. For visual assessment, the average score of the pretreatment group was significantly less than that of the posttreatment and control groups. For quantitative analysis, the average oxygen saturation of the pretreatment group was significantly higher than that of the posttreatment and control groups, while no significant difference was observed between the posttreatment and control groups. Conclusion: After treatment, normalization of increased oxygen saturation was noninvasively observed by using SW imaging in patients with spinal AVM. SW imaging can be a useful tool for the assessment of treatment efficacy in patients with spinal AVM. (C)RSNA, 2010
• Detection of Normal Spinal Veins by Using Susceptibility-Weighted Imaging

  Kinya Ishizaka, Kohsuke Kudo, Noriyuki Fujima, Yuri Zaitsu, Rie Yazu, Khin Khin Tha, Satoshi Terae, E. Mark Haacke, Makoto Sasaki, Hiroki Shirato

  JOURNAL OF MAGNETIC RESONANCE IMAGING 31 1 32 - 38 2010年01月 [査読有り][通常論文]
   

  Purpose: To evaluate the visualization of the spinal veins using susceptibility-weighted imaging (SWI). Materials and Methods: A 1.5-T magnet equipped with a spine matrix coil was used. Axial SWI scans of 20 healthy volunteers were obtained with a three-dimensional fast low-angle shot (3D-FLASH) sequence. Maximum intensity projection (MIP) of the phase images were reconstructed and five MIP images (at the levels of T11, T11/12, T12, T12/L1, and L1) were selected for the evaluation. The anterior median vein (AMV), posterior median vein (PMV), anterior radiculomedullary vein (ARV), posterior radiculomedullary vein (PRV), and sulcal vein (SV) were evaluated using a 4-grade scale (0, none; 1, weak; 2, moderate: and 3, prominent). Results: The AMV was detected in all the subjects (100%). The detection rates of the other veins were lower: PMV, 65%: right ARV. 45%: left ARV, 15%; right PRV. 10%; left PRV, 30%; and SV, 0%. The average scores for AMV, PMV, right ARV. left ARV, right PRV, left PRV, and SV were 0.98, 0.24, 0.20, 0.08, 0.08, 0.14, and 0, respectively. Conclusion: SWI of the spine is feasible. The extrinsic spinal veins can be visualized by SWI without using contrast materials.
• Susceptibility-weighted imaging of cerebral fat embolism.

  Yuri Zaitsu, Satoshi Terae, Kohsuke Kudo, Khin Khin Tha, Mineji Hayakawa, Noriyuki Fujima, Daisuke Yoshida, Akiko Tsukahara, Hiroki Shirato

  Journal of computer assisted tomography 34 1 107 - 12 2010年01月 [査読有り][通常論文]
   

  Cerebral fat embolism (CFE) causes microinfarcts, vasogenic edema, and petechiae in the brain. Conventional magnetic resonance imaging has been reported to effectively visualize microinfarcts and vasogenic edema in CFE, but not petechiae. We report 3 cases of CFE in which susceptibility-weighted imaging distinctly demonstrated multiple minute hypointense foci in the brain, which were interpreted as petechiae, susceptibility-weighted imaging is a useful adjunct to conventional magnetic resonance imaging for the evaluation of CFE.
• Small bowel strangulation caused by parasitic peritoneal strand

  N Masui, N Fujima, T Hasegawa, S Kigawa, N Kagei, K Nagashima, Y Shimizu

  PATHOLOGY INTERNATIONAL 56 6 345 - 349 2006年06月 [査読有り][通常論文]
   

  A 51-year-old woman with a history of eating raw fish over a period of 2 weeks developed a progressive abdominal pain and leukocytosis with signs of small bowel obstraction. Eosinophilia was not detected in the peripheral blood. The patient underwent surgery to clarify the possibility of ileus. Partial small bowel near the ileum was trapped by a peritoneal strand and was strangulated for approximately 30 cm in length with congestion and edema. The removal of the strand easily released the strangulation and the small bowel returned to a normal appearance. Pathologically, the strand consisted of granulomatous inflammation with a wide zone of necrosis containing a dead ghost feature of a parasite in its center. The necrosis was surrounded by palisading spindle cells with largely lymphocytic inifiltration and a few eosinophils. In the parasite, there presented the polymyalian type muscle layer, ventricles and Renette cells, which suggested that the parasite is compatible with the third stage larva of Anisakis type I, leading to the diagnosis of ectopic anisakidosis. It should be noted that, on rare occasions, Anisakis larva migrans can form a peritoneal strand with a wide zone of necrosis and cause strangulation ileus, especially in populations with the habit of eating raw fish.

MISC

• 無症候性で診断しえたCarotid webの1例

  池辺洋平, 原田太以佑, 藤間憲幸, 清水幸衣, 亀田浩之, 杉山拓, 工藤與亮 日本脳神経CI学会総会プログラム・抄録集 47th 2024年
• 気管食道科領域の画像・AI診断 頸部-気管食道領域の画像診断最前線

  藤間 憲幸 日本気管食道科学会会報 74 (2) 197 -197 2023年04月
• 【脊椎脊髄の先進的なMRI検査や解析】脊髄のSWI,造影MRA

  藤間 憲幸 脊椎脊髄ジャーナル 35 (10) 695 -700 2023年03月 

  ＜文献概要＞はじめに 磁化率強調画像(susceptibility weighted imaging:SWI)は局所の磁化率の変化を鋭敏に検出し画像化する撮像法である.造影MR angiography(MRA)は,造影剤を用いた血管撮像であり,近年のMR装置の進歩に伴い脊髄領域の細かな血管でも良好な描出が可能である.これらの技術は日常臨床でそれほど高頻度に用いられるものではないが,ある特定の疾患のアセスメントには非常に重要な役割を果たす.本稿では,脊椎脊髄領域をターゲットとしたSWIおよび造影MRAについて技術的概要および臨床的有用性に関して概説する.
• 髄膜腫におけるCD44の発現についての検討

  澤谷亮佑, 山口秀, 伊師雪友, 岡本迪成, 越前谷すみれ, 茂木洋晃, 藤間憲幸, 藤村幹 日本分子脳神経外科学会プログラム・抄録集 23rd 2023年
• 最新アプリケーションがもたらす臨床インパクト 頭部・頭頸部

  藤間 憲幸 映像情報Medical 54 (14) 77 -82 2022年12月
• Arterial Spin Labelingを用いた短時間Functional MRIの検討

  林 哲司, 浜口 明巧, 藤間 憲幸, 原田 太以佑 JART: 日本診療放射線技師会誌 69 (9) 1013 -1013 2022年09月
• 【絶対苦手分野にしない 頭蓋底周辺の画像診断】頭蓋底周辺の悪性腫瘍

  中川 純一, 藤間 憲幸 臨床画像 38 (9) 1002 -1012 2022年09月 

  ＜文献概要＞頭頸部悪性腫瘍は局在が頭蓋底やその周辺構造に近接する場合があり,画像診断による進展範囲の評価が重要である。病変の進行により,頸部間隙や頭蓋底の骨髄に認めるはずの脂肪が,病変に類似した濃度・信号の軟部組織に置き換わり,神経周囲進展では介在する骨孔・管の拡大や破壊,病変と連続した軟部組織・造影効果として認められる。
• 【絶対苦手分野にしない 頭蓋底周辺の画像診断】頭蓋底周辺の悪性腫瘍

  中川 純一, 藤間 憲幸 臨床画像 38 (9) 1002 -1012 2022年09月 

  ＜文献概要＞頭頸部悪性腫瘍は局在が頭蓋底やその周辺構造に近接する場合があり,画像診断による進展範囲の評価が重要である。病変の進行により,頸部間隙や頭蓋底の骨髄に認めるはずの脂肪が,病変に類似した濃度・信号の軟部組織に置き換わり,神経周囲進展では介在する骨孔・管の拡大や破壊,病変と連続した軟部組織・造影効果として認められる。
• Arterial Spin Labelingを用いた短時間Functional MRIの検討

  林 哲司, 浜口 明巧, 藤間 憲幸, 原田 太以佑 JART: 日本診療放射線技師会誌 69 (9) 1013 -1013 2022年09月
• 核医学～近未来核医学の向かう道-診断・治療の精度をあげる最新手法～ 核医学におけるAIの活用と課題

  平田 健司, 杉森 博行, 藤間 憲幸, 豊永 拓哉, 工藤 與亮 日本医学放射線学会秋季臨床大会抄録集 58回 S344 -S344 2022年08月
• 核医学〜近未来核医学の向かう道-診断・治療の精度をあげる最新手法〜 核医学におけるAIの活用と課題

  平田 健司, 杉森 博行, 藤間 憲幸, 豊永 拓哉, 工藤 與亮 日本医学放射線学会秋季臨床大会抄録集 58回 S344 -S344 2022年08月
• 【これを見つけたら即対応 重要疾患を読影で見きわめる】中枢神経領域

  池辺 洋平, 藤間 憲幸, 工藤 與亮 臨床画像 37 (12) 1390 -1402 2021年12月 

  ＜文献概要＞椎骨動脈解離は種々のシーケンスを用いて解離を同定する必要があり,3D-TSE(turbo spin-echo)法T1強調像やMR cisternographyが有用な場合がある。静脈血栓症は正常例や種々の疾患との鑑別が問題となり,診断確定には造影MRV(MR venography)が有用である。メトロニダゾール脳症は小脳歯状核の異常信号が特徴で,詳細な病歴の確認が重要である。低髄液圧症候群/脳脊髄液漏出症は髄液減少に伴う特徴的な所見を積極的に検索することで診断できる。
• 【Nuclear Medicine Today 2021 キーワードから展望する核医学の技術開発と臨床応用】人工知能(AI)の研究開発の現状と将来展望 1)腫瘍核医学におけるAI利用の動向

  平田 健司, 藤間 憲幸, 杉森 博行, 工藤 與亮 INNERVISION 36 (10) 17 -20 2021年09月
• 耳鼻咽喉科領域のMRI

  藤間 憲幸 耳鼻咽喉科臨床 補冊 (補冊157) 44 -44 2021年06月
• 【CTとMRIのサインから読み解く病態・病理II】頭頸部領域

  中川 純一, 藤間 憲幸 臨床放射線 66 (2) 131 -136 2021年02月
• 急性期血行再建術における非造影MRAによるアクセスルートの有用性

  小林 聡, 長内 俊也, 中山 若樹, 数又 研, 杉山 拓, 藤間 憲幸, 濱口 明巧, 中村 俊孝, 飛騨 一利 脳血管内治療 5 (Suppl.) 23 -23 2020年11月
• 【ビギナーのための頭頸部画像診断-Q&Aアプローチ-】所見からのアプローチ (Q2)CTで内部に低吸収域を伴うリンパ節腫大の鑑別を教えてください

  藤間 憲幸, 酒井 修 画像診断 40 (9) 934 -936 2020年07月
• 【ビギナーのための頭頸部画像診断-Q&Aアプローチ-】所見からのアプローチ (Q3)リンパ節の節外浸潤の画像所見と,その必要性を教えてください

  藤間 憲幸, 酒井 修 画像診断 40 (9) 937 -939 2020年07月
• Somatic malignant transformationが疑われたgerm cell tumor再発の1例

  高柳 歩, 原田 太以佑, 藤間 憲幸, 工藤 與亮, 岡田 宏美, 山口 秀, 小林 浩之 Japanese Journal of Radiology 38 (Suppl.) 7 -7 2020年02月
• 急性期血行再建術における非造影MRAによるアクセスルートの有用性

  小林聡, 長内俊也, 中山若樹, 数又研, 杉山拓, 藤間憲幸, 濱口明巧, 中村俊孝, 飛騨一利 脳血管内治療(Web) 5 (Supplement) 2020年
• 【MRI再入門-放射線科医のためのマストアイテム-Part1】頭部MRI:脳腫瘍と脱髄・炎症疾患

  藤間 憲幸, 清水 幸衣, 工藤 與亮 画像診断 40 (2) 180 -189 2020年01月 

  ＜文献概要＞Point ・脳腫瘍や脱髄・炎症疾患はMRI撮像プロトコールの幅が非常に広く,検査目的に応じてその内容を吟味する必要がある.・病態や疾患によって一般的な撮像法だけでなく,特殊撮像法がより有用となる場面があるため,その適応を熟知すべきである.・標的病変の形態や局在に応じて,冠状断像や矢状断像の追加,あるいは3D収集の利用を常に念頭に置いて,撮像内容を決定すべきである.
• 下錐体静脈洞サンプリングにおけるアクセスルートMR venography

  東海林 菊太郎, 長内 俊也, 藤間 憲幸, 牛越 聡, 茂木 洋晃, 伊師 雪友, 寳金 清博 脳血管内治療 4 (Suppl.) S217 -S217 2019年11月
• 血管内治療における非造影MRAと造影MRAによるアクセスルートの比較

  小林 聡, 長内 俊也, 中山 若樹, 数又 研, 藤間 憲幸, 中村 俊孝, 飛騨 一利 脳血管内治療 4 (Suppl.) S384 -S384 2019年11月
• 【進展経路からアプローチする頭頸部癌の画像診断】鼻副鼻腔癌に関連する進展経路 眼窩進展

  藤間 憲幸 画像診断 39 (8) 826 -827 2019年06月
• 【進展経路からアプローチする頭頸部癌の画像診断】鼻副鼻腔癌に関連する進展経路 眼窩尖部への進展

  藤間 憲幸 画像診断 39 (8) 828 -829 2019年06月
• 【進展経路からアプローチする頭頸部癌の画像診断】鼻副鼻腔癌に関連する進展経路 頭蓋底・頭蓋内進展

  藤間 憲幸 画像診断 39 (8) 830 -831 2019年06月
• 【進展経路からアプローチする頭頸部癌の画像診断】鼻副鼻腔癌に関連する進展経路 翼口蓋窩・神経周囲進展

  藤間 憲幸 画像診断 39 (8) 832 -834 2019年06月
• 【進展経路からアプローチする頭頸部癌の画像診断】鼻副鼻腔癌に関連する進展経路 翼状突起進展

  藤間 憲幸 画像診断 39 (8) 835 -837 2019年06月
• 17O標識水の第1相臨床試験 安全性および脳血流MRIの実現可能性に関する検討

  原田 太以佑, 工藤 與亮, 亀田 浩之, 佐藤 良太, 白猪 亨, 尾藤 良孝, 藤間 憲幸, 常田 慧徳, 野川 敏史, 前田 憲一郎, 林 宏至, 佐々木 真理 日本磁気共鳴医学会雑誌 39 (2) 66 -66 2019年05月
• 特徴的な画像所見を呈した鞍上部immature teratomaの1例

  藤井 宝顕, 原田 太以佑, 清水 幸衣, 藤間 憲幸, Tha Khin Khin, 工藤 與亮, 寺坂 俊介, 長 祐子, 白土 博樹 Japanese Journal of Radiology 37 (Suppl.) 4 -4 2019年02月
• くも膜下出血後にびまん性の白質障害を呈した1例

  古家 翔, 原田 太以佑, 清水 幸衣, 藤間 憲幸, Tha Khin Khin, 工藤 與亮, 月花 正幸, 中山 若樹, 白土 博樹 Japanese Journal of Radiology 37 (Suppl.) 10 -10 2019年02月
• 下錐体静脈洞サンプリングにおけるアクセスルートMR venography

  東海林菊太郎, 長内俊也, 藤間憲幸, 牛越聡, 茂木洋晃, 伊師雪友, 寳金清博 脳血管内治療(Web) 4 (Supplement) 2019年
• くも膜下出血後にびまん性の白質障害を呈した一例

  古家 翔, 原田 太以佑, 清水 幸衣, 藤間 憲幸, Tha Khin Khin, 工藤 與亮, 月花 正幸, 中山 若樹, 白土 博樹 核医学 55 (1) 40 -40 2018年12月
• 血管内治療におけるMRAとCTAによるアクセスルートの比較

  小林 聡, 長内 俊也, 中山 若樹, 鐙谷 武雄, 数又 研, 藤間 憲幸, 清水 幸衣, 大野 浩太, 宝金 清博 脳血管内治療 3 (Suppl.) S268 -S268 2018年11月
• 血管内治療におけるMRAとCTAによるアクセスルートの比較

  小林 聡, 長内 俊也, 中山 若樹, 鐙谷 武雄, 数又 研, 藤間 憲幸, 清水 幸衣, 大野 浩太, 宝金 清博 脳血管内治療 3 (Suppl.) S268 -S268 2018年11月 [査読無し][通常論文]
  
• 頭蓋内硬膜動静脈瘻に対する4D-MRAの検討

  東海林 菊太郎, 長内 俊也, 藤間 憲幸, 牛越 聡, 寳金 清博 脳血管内治療 3 (Suppl.) S203 -S203 2018年11月 [査読無し][通常論文]
  
• 頭頸部癌の画像診断 最近の話題

  藤間 憲幸 断層映像研究会雑誌 45 (1) 2 -2 2018年09月
• 磁化率アーチファクトを応用したVessel encode ASL法についての検討

  林 哲司, 藤間 憲幸, 浜口 明巧, 飛弾 和弘, 益塚 俊秀 JART: 日本診療放射線技師会誌 65 (9) 1068 -1068 2018年09月
• 【Step up MRI 2018 MRI新技術 基礎から臨床への橋渡し】MRIの新技術 臨床編 頭部領域におけるMRIの新技術と臨床応用 定量的磁化率マッピングの臨床応用

  原田 太以佑, 藤間 憲幸, 工藤 與亮 INNERVISION 33 (9) 37 -40 2018年08月 

  磁化率は組織固有の物理的性質であり、その画像化として磁化率強調画像(susceptibility weighted imaging:SWI)や位相差強調画像(phase difference enhanced imaging:PADRE)が定性画像として用いられている。近年では、MRIを用いた定量化が一つのテーマとなっており、定量的磁化率マッピング(quantitative susceptibility mapping:QSM)は、磁化率を定量的に評価できる方法として、ここ数年で臨床研究の報告が急増している。本稿では、QSMの臨床応用と最近の知見について概説する。(著者抄録)
• Refresher Course 中枢神経領域におけるarterial spin labelingの画像所見

  藤間 憲幸 画像診断 38 (7) 713 -723 2018年05月 

  ＜文献概要＞全国的な3T-MRIの普及に伴ってarterial spin labeling(ASL)の画像読影の機会が増えつつあり,ASLが特に有用な疾患,画像所見のパターンを熟知する必要性が高まっている.本稿では,ASLの基本的な概要から中枢神経領域における重要な疾患,画像所見を概説する.
• 頭頸部癌における画像診断の進歩と今後の展望 頭頸部癌のMRI最前線

  藤間 憲幸 頭頸部癌 44 (2) 110 -110 2018年05月
• 30年後の再発が疑われる脊髄Germinomaの1例

  木野田 直也, 原田 太以佑, 吉田 篤司, 清水 幸衣, 藤間 憲幸, 工藤 興亮, Khin Khin Tha, 白土 博樹, 山口 秀, 小林 浩之, 寺坂 俊介, 岡田 宏美, 畑中 佳奈子 Japanese Journal of Radiology 36 (Suppl.) 3 -3 2018年02月
• 長期間経過を追えたCerebral Amyloid Angiopathyの1例

  常田 慧徳, 原田 太以佑, 吉田 篤司, 清水 幸衣, 藤間 憲幸, 工藤 與亮, 西村 洋昭, 佐々木 秀直, Khin Khin Tha, 白土 博樹 Japanese Journal of Radiology 36 (Suppl.) 13 -13 2018年02月
• 亜急性連合性脊髄変性症の1例

  長島 諒太, 原田 太以佑, 吉田 篤司, 清水 幸衣, 藤間 憲幸, 工藤 與亮, Khin Khin Tha, 白土 博樹, 西村 洋昭, 佐々木 秀直 Japanese Journal of Radiology 36 (Suppl.) 16 -16 2018年02月
• 頭蓋内硬膜動静脈瘻に対する4D-MRAの検討

  東海林菊太郎, 長内俊也, 藤間憲幸, 牛越聡, 寳金清博 脳血管内治療(Web) 3 (Supplement) 2018年
• 【薬物治療に起因する諸病態の画像所見】中枢神経

  原田 太以佑, 藤間 憲幸, 工藤 與亮 臨床画像 33 (10) 1116 -1129 2017年10月 

  薬物治療に関連する中枢神経病変は非常に多彩であるが,画像診断医が薬剤性病変の可能性を言及することが肝要である。本稿では最近よく話題となっている分子標的薬に焦点をあてつつ,日常臨床でしばしば見かける薬剤関連病変の画像所見を概説する。(著者抄録)
• 高時間分解能非造影4D-MRAを用いたWillis動脈輪内の血流可視化の試み

  葛西 克彦, 石坂 欣也, 藤間 憲幸, 堀江 達則 日本放射線技術学会雑誌 73 (9) 809 -809 2017年09月 [査読無し][通常論文]
  
• 成人発症のAlexander病の1例

  阿部 恵, 西村 洋昭, 長沼 亮滋, 白井 慎一, 高橋 育子, 松島 理明, 加納 崇裕, 矢部 一郎, 原田 太以佑, 藤間 憲幸, 工藤 與亮, 吉田 誠克, 佐々木 秀直 臨床神経学 57 (6) 322 -322 2017年06月 [査読無し][通常論文]
  
• DW-ASLを用いた脳虚血領域におけるwater permeabilityの評価

  藤間 憲幸, 奥秋 知幸, 青池 拓哉, 青池 寿々子, 杉森 博行, 工藤 與亮 日本磁気共鳴医学会雑誌 37 (1) 15 -17 2017年02月 [査読無し][通常論文]
   

  脳虚血性病変を有する8例(男性7名、女性1名、53〜73歳)を対象とした。5例はdiffusion-weighted arterial spin labelingの撮像日の3年前に全脳のT2強調像、FLAIR像での評価を行った。それぞれのROIごとにT2強調像、FLAIR像で虚血の程度に応じて、3段階のグレード評価を行い、殆ど虚血を認めないNI群、虚血性変化が軽度のMI群、虚血性変化が中等度ないし高度のSI群に分けた。それぞれのROIごとに虚血の変化を比較して虚血の変化に応じて二つのグレードに分割した(NP群;3年間で虚血が殆ど変化なし、P群;3年間で虚血が拡大)。DW-ASLの撮像は問題なく施行可能であった。104個のROIによる3段階の虚血の程度の評価に関してKw値を算出し、SI群はMI群、NI群と比較して有意に高かった。3年間の虚血の進行の程度に関しては、5例における65個のROIの評価の結果、P群はNP群と比較して、有意にKwの値が高かった。視覚的にはT2強調像やFLAIR像で認める高信号域よりやや広い領域でwater permeabilityの変化がみられる領域が観察される傾向があった。
• 成人発症のAlexander病の1例

  阿部恵, 西村洋昭, 長沼亮滋, 白井慎一, 高橋育子, 松島理明, 加納崇裕, 矢部一郎, 原田太以佑, 藤間憲幸, 工藤與亮, 吉田誠克, 佐々木秀直 臨床神経学(Web) 57 (6) 2017年
• 【高精度放射線治療のための最適な画像診断に向けて】頭頸部腫瘍の治療に必要な画像診断

  藤間 憲幸 臨床放射線 61 (13) 1743 -1750 2016年12月
• 定量的磁化率マッピングで脳の構造と酸素代謝をみる

  工藤 與亮, 藤間 憲幸, Khin Khin Tha, 清水 幸衣, 原田 太以佑, 吉田 篤司 臨床神経学 56 (Suppl.) S62 -S62 2016年12月
• 【Step up MRI 2016 明日の臨床に向けた撮像法、今日の検査に役立つ撮像テクニック】明日の臨床に向けた撮像法の実際 頭部非造影MRA advanced ASL-based MRAの臨床応用

  藤間 憲幸 INNERVISION 31 (9) 5 -8 2016年08月 

  頭部の非造影MRAはtime of flight(以下、TOF)-MRAが日常臨床では頻用されているが、近年はそのシーケンスデザインにさまざまな工夫を凝らした新技術の報告が相次いでいる。MRAの技術背景には流入血液のinflow効果を標的とするもの、流れる血液のdephasingによって標的血管を低信号化させて強調するもの、phase contrast法を用いたものなどさまざまな技術が存在し、さらには通常のMRAの複合技術としてcompressed sensingといった高速撮像技術の併用も注目されつつある。本稿では、その中でも日常臨床で使われるようになってきた技術としてarterial spin labeling(以下、ASL)-based MRAを中心に、注目されつつある付加的テクニックを含めて概説したい(MR画像はすべてフィリップス社製「Achieva」で撮像)。(著者抄録)
• 喉頭癌の画像診断

  藤間 憲幸 日本医学放射線学会秋季臨床大会抄録集 52回 S435 -S436 2016年08月
• 【頭頸部血管イメージングup to date】4D-MRA

  藤間 憲幸 臨床画像 32 (4) 429 -437 2016年04月
• 頭部非造影4D-MRAにおける早期描出能が改善された時相間可変flip angle法と固定flip angle法の比較と検討

  川角 恵里奈, 杉森 博行, 石坂 欣也, 藤間 憲幸, 小原 真 北海道放射線技術雑誌 (80) 18 -19 2016年04月 [査読無し][通常論文]
  
• Spin labeling法を用いた脳脊髄液動態イメージング法の検討 背景信号抑制の試み

  平山 博之, 杉森 博行, 藤間 憲幸, 奥秋 知幸 北海道放射線技術雑誌 (80) 32 -33 2016年04月 [査読無し][通常論文]
  
• 【神経放射線診断-最新情報と読影のピットフォール】MRI Perfusion MRI Arterial spin labeling(ASL)とdynamic susceptibility contrast(DSC)を中心に

  清水 幸衣, 工藤 與亮, 藤間 憲幸 Clinical Neuroscience 33 (10) 1125 -1128 2015年10月
• 頭部非造影4D-MRAにおける早期描出能が改善された時相間可変flip angle法と固定flip angle法の比較と検討

  川角 恵里奈, 杉森 博行, 石坂 欣也, 水戸 寿々子, 高森 清華, 藤間 憲幸, 小原 真 北海道放射線技術雑誌 (79) 88 -88 2015年10月
• Spin labeling法を用いた脳脊髄液動態イメージングにおける背景脳脊髄液信号抑制の試み

  平山 博之, 杉森 博行, 藤間 憲幸, 石坂 欣也, 水戸 寿々子, 高森 清華, 奥秋 知幸 北海道放射線技術雑誌 (79) 103 -103 2015年10月
• もやもや病周術期におけるASL-4DMRAを用いた脳循環評価

  内野 晴登, 伊東 雅基, 数又 研, 藤間 憲幸, 中山 若樹, 宝金 清博 脳循環代謝 27 (1) 131 -131 2015年10月
• Phase-sensitive inversion recovery(PSIR)法の撮像パラメータが白質・灰白質の信号強度に与える影響の検討

  野畑 圭亮, 藤原 太郎, 杉森 博行, 石坂 欣也, 青池 拓哉, Wang Jeff, 藤間 憲幸 日本放射線技術学会雑誌 71 (9) 855 -856 2015年09月
• FIESTA cycled phases(FIESTA-C)を用いた3D画像処理における頭蓋骨描出とその臨床的有用性についての検討

  林 哲司, 浜口 明巧, 藤間 憲幸 日本放射線技術学会雑誌 71 (9) 884 -885 2015年09月
• 【ビギナーのための頭部画像診断-Q&Aアプローチ-】疾患別 小児や若年者の脳血管障害をみた時に考えられる疾患は何ですか?

  藤間 憲幸 画像診断 35 (10) 1272 -1273 2015年08月
• 【脊椎脊髄の感染・炎症】髄膜炎・硬膜外膿瘍

  藤間 憲幸 脊椎脊髄ジャーナル 28 (6) 541 -546 2015年06月
• 放射線科医が頭部CTに求めるもの

  藤間 憲幸 日本放射線技術学会雑誌 71 (5) 449 -455 2015年05月
• BUT短縮型ドライアイ患者のfunctionalMRIによる脳機能解析を施行した1例

  田川 義晃, 大口 剛司, Tha Khin Khin, 藤間 憲幸, 敦賀 健吉, 加藤 類, 木嶋 理紀, 岩田 大樹, 水内 一臣, 田川 義継, 石田 晋 日本眼科学会雑誌 119 (臨増) 266 -266 2015年03月 [査読無し][通常論文]
  
• 頭頸部における扁平上皮癌と悪性リンパ腫の腫瘍血流の違い

  亀田 浩之, 藤間 憲幸, 吉川 仁人, 吉田 篤司, 清水 幸衣, 吉田 大介, 塚原 亜希子, 工藤 與亮, Tha Khin Khin, 白土 博樹 Japanese Journal of Radiology 33 (Suppl.) 1 -1 2015年02月
• 発熱と骨病変が先行した小児白血病の1例

  藪崎 哲史, 宮本 憲幸, 白土 博樹, 真鍋 徳子, 藤間 憲幸, 菊池 穏香, 坂本 圭太, 三村 理恵, 加藤 芙美, 工藤 與亮, 佐藤 智信, 長 祐子, 井口 晶裕 Japanese Journal of Radiology 33 (Suppl.) 2 -2 2015年02月
• 孤発性筋萎縮性側索硬化症における上行性感覚路のDTI解析

  清水 幸衣, 藤間 憲幸, 塚原 亜希子, 工藤 與亮, 矢部 一郎, 廣谷 真, 佐々木 秀直, Tha KhinKhin, 白土 博樹 Japanese Journal of Radiology 33 (Suppl.) 9 -9 2015年02月
• Spin labeling法を用いた脳脊髄液動態イメージングの検討

  平山 博之, 杉森 博行, 藤間 憲幸, 奥秋 知幸 日本放射線技術学会総会学術大会予稿集 71回 174 -174 2015年02月
• 頭頸部領域におけるflip angleの至適化及び、撮像角度による脂肪抑制効果の検討

  川角 恵里奈, 水戸 寿々子, 藤間 憲幸, 石坂 欣也, 藤原 太郎, 高森 清華, 杉森 博行 日本放射線技術学会総会学術大会予稿集 71回 225 -225 2015年02月
• 【CT・MRI"戦略的"活用ガイド】特殊検査とオーダーのポイント 脳の拡散強調画像と灌流強調画像

  吉田 篤司, 藤間 憲幸, 工藤 與亮 Medicina 51 (11) 217 -224 2014年11月
• 頭部double inversion recovery法における撮像パラメータが白質・脳脊髄液の信号強度に与える影響の検討

  野畑 圭亮, 藤原 太郎, 藤間 憲幸, 杉森 博行, 高森 清華, 石坂 欣也, 青池 拓哉 日本放射線技術学会雑誌 70 (9) 1046 -1046 2014年09月
• 放射線科医が頭部CTに求めるもの(教育講演,テーマ:頭部CT撮影を再考する,第63回放射線撮影分科会)

  藤間 憲幸 放射線撮影分科会誌 (63) 2 -5 2014年09月 [査読無し][通常論文]
  
• 【画像診断パーフェクトガイド 読影のポイントとピットフォール】部位別診断法 鼻・副鼻腔 鼻・副鼻腔癌

  藤間 憲幸, 本間 明宏 耳鼻咽喉科・頭頸部外科 86 (5) 149 -155 2014年04月
• 【マルチモダリティによるHead & Neck Imaging 2014 臨床編 最新技術が臨床にもたらす変革とベネフィット】MRIのストラテジー&アウトカム 臨床施設からの報告 脳血管障害 ASLによる脳血流動態評価

  藤間 憲幸 INNERVISION 29 (5) 33 -36 2014年04月 

  ASLはその非侵襲性から、特に急性期に頻回の評価が必要となる脳血管障害において重要な役割を持つ。pseudo-continuous ASL(pCASL)の普及に伴いpulsed ASL(PASL)は衰退しつつあるが、multi-phaseによる経時的な評価やlabeling slabの自由度を生かしたvessel selective ASLなど、PASLでより威力を発揮する技術もあり、その存在感はなくなったわけではない。また、近年ではラベルされたスピンが血管内にある早い時相から連続的な撮像を行い、時間分解能を持ったMRA(4D-MRA)を取得する技術も広がりつつある。本稿では、当院で使用しているフィリップス社製「Achieva 3.0T TX」で得られた知見を基に、これらのASLの技術の概説と、脳血管障害に対して持つ臨床的な有用性について述べる。(著者抄録)
• 頭部3D-DIR法における適正delay timeの検討

  野畑 圭亮, 藤原 太郎, 藤間 憲幸, 杉森 博行, 濱口 裕行, 吉田 博一, 平山 博之 北海道放射線技術雑誌 (76) 46 -47 2014年03月 [査読無し][通常論文]
  
• 飽和パルスを用いた4-dimensional magnetic resonance angiography(4D-MRA)最適化の検討

  杉森 博行, 藤間 憲幸, 濱口 裕行, 藤原 太郎, 吉田 博一, 中村 麻名美, 坂田 元道 北海道放射線技術雑誌 (76) 64 -65 2014年03月 [査読無し][通常論文]
  
• MR灌流画像における脳腫瘍CBV値の悪性度分別能評価 解析ソフトウェア間の比較(第3報)

  上野 育子, 工藤 與亮, 佐々木 真理, 山下 典生, Goodwin Jonathan, 平井 俊範, 藤間 憲幸 Japanese Journal of Radiology 32 (Suppl.) 8 -8 2014年02月
• 頭頸部腫瘍への拡散強調系シーケンスの応用

  藤間 憲幸 Japanese Journal of Radiology 32 (Suppl.) 8 -8 2014年02月
• ASL-4D MRAを用いたもやもや病患者の周術期血行動態評価

  内野 晴登, 伊東 雅基, 数又 研, 中山 若樹, 藤間 憲幸, 七戸 秀夫, 鐙谷 武雄, 宝金 清博 脳循環代謝 25 (1) 147 -147 2013年11月 [査読無し][通常論文]
  
• 飽和パルスを用いた4-dimensional magnetic resonance angiography(4D-MRA)最適化の検討

  杉森 博行, 濱口 裕行, 藤原 太郎, 吉田 博一, 藤間 憲幸, 中村 麻名美, 坂田 元道 北海道放射線技術雑誌 (75) 99 -99 2013年10月
• 頭部3D-DIR法における適正delay timeの検討

  野畑 圭亮, 藤原 太郎, 杉森 博行, 濱口 裕行, 吉田 博一, 平山 博之, 藤間 憲幸 北海道放射線技術雑誌 (75) 101 -101 2013年10月
• 【脊椎脊髄の解剖と疾患】(第2章)知っておくと役立つ特殊検査 MRI 磁化率強調画像

  藤間 憲幸 脊椎脊髄ジャーナル 26 (4) 421 -427 2013年04月
• Laterality of the Corticospinal Tract and the Influence of Handedness : Findings of a DTI Study

  THA Khin Khin, TERAE Satoshi, HAMAGUCHI Hiroyuki, ISHIZAKA Kinya, POPY Kawser Akter, HIROTANI Makoto, SUGIMORI Hiroyuki, FUJIMA Noriyuki, YOSHIDA Atsushi, MINOWA Kazuyuki, SUZUKI Yuriko, SHIRATO Hiroki 日本磁気共鳴医学会雑誌 33 (1) 33 -34 2013年02月15日
• 頭頸部腫瘍におけるArterial spin-labelingの有用性の検討

  藤間 憲幸 Japanese Journal of Radiology 31 (Suppl.I) 5 -5 2013年02月
• 脳腫瘍におけるMR灌流画像のCBV評価 解析ソフトウェア間の比較

  上野 育子, 工藤 與亮, 佐々木 真理, 阿久津 仁美, 齊藤 絵里奈, 千葉 映奈, 平井 俊範, 藤間 憲幸, 江原 茂 Japanese Journal of Radiology 31 (Suppl.I) 5 -5 2013年02月
• MR灌流画像における脳腫瘍悪性度別のCBV評価 解析ソフトウェア間の比較(第2報)

  上野 育子, 工藤 與亮, 佐々木 真理, 阿久津 仁美, 齊藤 絵里奈, 千葉 映奈, 平井 俊範, 藤間 憲幸 Japanese Journal of Radiology 31 (Suppl.I) 13 -13 2013年02月
• 口腔癌における超選択的シスプラチン動注化学療法後のセンチネルリンパ節内プラチナ濃度測定

  坂下 智博, 本間 明宏, 折舘 伸彦, 鈴木 清護, 畠山 博充, 加納 里志, 水町 貴諭, 吉田 大介, 藤間 憲幸, 福田 諭 北海道醫學雜誌 = Acta medica Hokkaidonensia 87 (6) 261 -261 2012年11月01日 [査読無し][通常論文]
  
• 【押さえておきたいMRIの基本とピットフォール】Flow voidの仕組みとピットフォール

  藤間 憲幸, 寺江 聡 脊椎脊髄ジャーナル 25 (9) 873 -880 2012年09月 [査読無し][通常論文]
  
• 【Step up MRI 2012 機能評価と機能画像の架け】機能画像を得るための工夫 dynamic susceptibility contrast(DSC)とASLの使い方、使い分け 脳疾患における血流動態評価

  藤間 憲幸, 工藤 與亮 INNERVISION 27 (9) 44 -47 2012年08月 

  血液灌流は脳実質の機能的な情報を含む重要な評価項目の1つであり、多岐にわたる脳疾患でその有用性が示されている。MRIを用いた灌流画像は、造影剤を用いて施行するdynamic susceptibility contrast(DSC)法と、血液を内因性のトレーサーとして使用するarterial spin labeling(ASL)法の2つに大別される。従来、灌流画像の取得は、DSC法がその大部分を占めていたが、3T MRIの普及とともにASL法の使用頻度が大きく増加している。DSC法とASL法にはそれぞれの長所と短所があり、例えばDSC法はガドリニウム(Gd)造影剤を用いるため侵襲的であるが、ASLは完全に非侵襲的であり、繰り返し撮像することも可能である。しかし、DSC法と比べてASL法は原理的にSNRが非常に低く、特に遅延血流の評価は困難な場合が多い。実臨床では、DSC法、ASL法それぞれの原理や特性を理解して、疾患ごとに使い分ける必要がある。本稿では、DSC法とASL法それぞれの原理的な解説、画像取得における工夫や脳疾患における使い分けについて概説する。(著者抄録)
• 脊髄腫瘍と間違いやすい疾患

  藤間 憲幸, 寺江 聡 日本医学放射線学会秋季臨床大会抄録集 48回 S497 -S497 2012年08月 [査読無し][通常論文]
  
• 【すぐ役立つ救急のCT・MRI】頭部外傷 脳挫傷(軽症、中等度、重症)

  藤間 憲幸, 工藤 興亮 画像診断 別冊 (すぐ役立つ救急のCT・MRI) 68 -69 2012年04月
• 【すぐ役立つ救急のCT・MRI】頭部外傷 出血性脳挫傷

  藤間 憲幸, 工藤 興亮 画像診断 別冊 (すぐ役立つ救急のCT・MRI) 70 -71 2012年04月
• 【すぐ役立つ救急のCT・MRI】頭部外傷 遅発性外傷性脳内血腫(DTICH)

  藤間 憲幸, 工藤 興亮 画像診断 別冊 (すぐ役立つ救急のCT・MRI) 72 -73 2012年04月
• 【すぐ役立つ救急のCT・MRI】頭部外傷 びまん性軸索損傷/びまん性脳腫脹

  藤間 憲幸, 工藤 興亮 画像診断 別冊 (すぐ役立つ救急のCT・MRI) 74 -75 2012年04月
• 【すぐ役立つ救急のCT・MRI】頭部外傷 慢性硬膜下血腫

  藤間 憲幸, 工藤 興亮 画像診断 別冊 (すぐ役立つ救急のCT・MRI) 76 -77 2012年04月
• 正常人における1.5T MRI T2強調横断像での被殻外側の線状高信号の検討

  Tha Khin Khin, 寺江 聡, 塚原 亜希子, 森田 亮, 坂本 圭太, 原田 八重, 吉田 大介, 財津 有里, 藤間 憲幸, 白土 博樹 Japanese Journal of Radiology 30 (Suppl.I) 1 -1 2012年02月 [査読無し][通常論文]
  
• 3T装置での脳転移スクリーニングのための造影3D-MRIの撮像法の検討 T1-VISTA法とT1-FLAIR法との比較

  吉田 篤司, 塚原 亜希子, 吉田 大介, 曽山 武士, 原田 慶一, 財津 有里, 藤間 憲幸, 寺江 聡, Tha Khin Khin, 白土 博樹 Japanese Journal of Radiology 30 (Suppl.I) 12 -12 2012年02月 [査読無し][通常論文]
  
• 全脳照射後の大脳白質障害:拡散テンソルによる経時的変化の検討

  タ キンキン, 寺江聡, 小野寺俊輔, 青山英史, ポピ コサアクタ, 藤間憲幸, 財津有里, 塚原亜希子, 吉田大介, 白土博樹 日本神経放射線学会プログラム・抄録集 41st 111 2012年 [査読無し][通常論文]
  
• Diffusion Tensor Imaging Characteristics of Normal Human Cervical Spinal Cord at 3T

  THA Khin K., TERAE Satoshi, ISHIZAKA Kinya, OKUAKI Tomoyuki, HIROTANI Makoto, FUJIMA Noriyuki, TSUKAHARA Akiko, SHIRATO Hiroki 日本磁気共鳴医学会雑誌 31 (1) 70 -70 2011年02月15日
• 3T装置での脳転移スクリーニング用の造影3D-MRIの撮像法の検討 T1-VISTA法とT1-FLAIR法との比較

  吉田 篤司, Tha Khin Khin, 塚原 亜希子, 吉田 大介, 曽山 武士, 原田 慶一, 財津 有里, 藤間 憲幸, 寺江 聡, 白土 博樹 日本医学放射線学会学術集会抄録集 70回 S243 -S243 2011年02月 [査読無し][通常論文]
  
• 頭頸部癌におけるアンジオCT Conventional CTとConebeam CTの比較検討

  吉田 大介, 藤間 憲幸, 財津 有里, Tha Khin Kihn, 寺江 聡, 白土 博樹, 工藤 與亮 Japanese Journal of Radiology 29 (Suppl.I) 4 -4 2011年01月 [査読無し][通常論文]
  
• T1強調像で高信号を呈した脳トキソプラズマ症の1例

  安井 太一, 寺江 聡, 藤間 憲幸, 財津 有里, Tha Khin Khin, 吉田 大介, 塚原 亜希子, 白土 博樹 Japanese Journal of Radiology 29 (Suppl.I) 10 -10 2011年01月 [査読無し][通常論文]
  
• 拡散テンソルによる難治性うつ病における大脳白質障害の検討

  Tha Khin Khin, 寺江 聡, 藤間 憲幸, 財津 有里, 白土 博樹, 井上 猛, 中川 伸, 小山 司, 宮本 環, 相馬 広幸, 矢部 一郎 Japanese Journal of Radiology 29 (Suppl.I) 4 -4 2011年01月 [査読無し][通常論文]
  
• 【Foix-Alajouanine症候群】Foix-Alajouanine症候群の画像診断

  宮坂 和男, 藤間 憲幸 神経内科 73 (3) 227 -233 2010年09月
• MRIの位相情報を利用した定量的脳血流マップ 手計算との比較

  谷津 リエ, 財津 有里, 藤間 憲幸, 白土 博樹, 寺江 聡, 石坂 欣也, 工藤 與亮, 佐々木 真理 Japanese Journal of Radiology 28 (Suppl.I) 12 -12 2010年07月 [査読無し][通常論文]
  
• 頭頸部癌におけるアンジオCT Conventional CTとConebeam CTの比較検討

  吉田 大介, 工藤 與亮, 藤間 憲幸, 財津 有里, Tha Khin Khin, 寺江 聡, 白土 博樹 日本医学放射線学会学術集会抄録集 69回 S278 -S279 2010年02月 [査読無し][通常論文]
  
• 【頭蓋内の境界病変 ここをどう鑑別する?】脳腫瘍と出血性脳血管障害

  藤間 憲幸, 吉田 大介, 寺江 聡 臨床画像 25 (11) 1202 -1213 2009年11月 [査読無し][通常論文]
  
• 脊髄AVMにおける磁化率強詞画像(SWI)の有用性の検討

  藤間憲幸, 工藤興亮, THA Khin Khin, 塚原亜希子, 寺江聡, 白土博樹 Radiat Med 27 (Supplement 1) 4 2009年04月25日 [査読無し][通常論文]
  
• 脊髄AVMにおける磁化率強調画像(SWI)の有用性の検討

  藤間 憲幸, 工藤 興亮, Tha Khin Khin, 塚原 亜希子, 寺江 聡, 白土 博樹 Japanese Journal of Radiology 27 (Suppl.) 4 -4 2009年04月
• 脊髄AVMの術前評価における3D CTAの有用性の検討

  財津 有里, 浅野 剛, 寺江 聡, 藤間 憲幸, 吉田 大介, 飛騨 一利, 白土 博樹 日本医学放射線学会学術集会抄録集 68回 S329 -S330 2009年02月 [査読無し][通常論文]
  
• SWIを用いた定量的脳血流マップの開発

  工藤 與亮, 谷津 リエ, 石坂 欣也, 財津 有里, 藤間 憲幸, 寺江 聡, 佐々木 真理 日本磁気共鳴医学会雑誌 29 (1) 22 -22 2009年02月 [査読無し][通常論文]
  
• 拡散テンソル画像法における多系統萎縮症のテント上白質病変の検出

  タ キンキン, 寺江聡, 矢部一郎, 宮本環, 相馬広幸, 財津有里, 藤間憲幸, 佐々木秀直, 白土博樹 日本神経放射線学会プログラム・抄録集 38th 142 2009年 [査読無し][通常論文]
  
• 画像診断と病理 強皮症に伴う心筋症

  藤間 憲幸, 大山 徳子, 榊原 守, 納谷 昌直, 絹川 真太郎, 久保田 佳奈子, 松野 吉宏 画像診断 28 (13) 1402 -1403 2008年11月 [査読無し][通常論文]
  
• 64列および4列のCT angiographyでの肝移植ドナーにおける肝動脈描出能の比較検討

  藤間 憲幸, 小野寺 祐也, 白土 博樹 Radiation Medicine 26 (Suppl.I) 13 -13 2008年04月
• 動態追跡照射時の肺腫瘍の動きに関連する因子の検討

  小野寺 祐也, 西岡 典子, 安田 耕一, 藤間 憲幸, 鬼丸 力也, 清水 伸一, 白土 博樹 日本医学放射線学会学術集会抄録集 67回 S193 -S193 2008年02月
• 脊髄AVMにおける磁化率強調画像(SWI)の有用性の検討

  藤間 憲幸, 工藤 與亮, 寺江 聡, 財津 有里, Tha Khin Khin, 塚原 亜希子, 浅野 毅, 吉田 大介, 飛騨 一利, 白土 博樹 日本医学放射線学会学術集会抄録集 67回 S241 -S241 2008年02月 [査読無し][通常論文]
  
• 呼吸負荷SWIを用いた定量的脳血流評価法の検討

  石坂欣也, 工藤與亮, 藤間憲幸, 谷津リエ, 尾松美香, 寺江聡, 白土博樹 日本放射線技術学会総会学術大会予稿集 64th 173 2008年 [査読無し][通常論文]
  
• SWIによる薬物および生理的負荷に対する脊髄静脈の描出変化および定量化

  藤間憲幸, 工藤與亮, 寺江聡, 財津有里, THA Khin Khin, 塚原亜希子, 吉田大介, 浅野剛, 谷津リエ, 石坂欣也, 白土博樹 日本神経放射線学会プログラム・抄録集 37th 96 2008年 [査読無し][通常論文]
  
• 脳脂肪塞栓症2例におけるSWI所見

  財津有里, 藤間憲幸, 塚原亜希子, ター キンキン, 工藤與亮, 寺江聡, 白土博樹 日本神経放射線学会プログラム・抄録集 37th 120 2008年 [査読無し][通常論文]
  
• 64列および4列のCT angiographyでの肝移植ドナーにおける肝動脈描出能の比較検討

  藤間 憲幸, 小野寺 祐也, 白土 博樹 核医学 44 (4) 389 -390 2007年11月
• Polycystic kidney diseaseに対するエタノールによる動脈塞栓術の経験

  作原 祐介, 阿保 大介, 長谷川 悠, 藤間 憲幸, 白土 博樹, 清水 匡 IVR: Interventional Radiology 22 (4) 503 -503 2007年10月
• Enlarged polycystic liverに対する動脈塞栓術の経験

  藤間 憲幸, 長谷川 悠, 作原 祐介, 阿保 大介, 白土 博樹, 清水 匡, 嶋村 剛 IVR: Interventional Radiology 22 (4) 503 -503 2007年10月
• 肝移植術時に作成された門脈下大静脈短絡路(PCシャント)をcoil塞栓できた1例

  阿保 大介, 作原 祐介, 長谷川 悠, 藤間 憲幸, 白土 博樹, 清水 匡, 嶋村 剛, 古川 博之 IVR: Interventional Radiology 22 (4) 503 -503 2007年10月
• 肝移植後膵液瘻による合併症に対しIVRにて複合的に対処した1例

  長谷川 悠, 阿保 大介, 作原 祐介, 藤間 憲幸, 白土 博樹, 清水 匡, 嶋村 剛, 古川 博之 IVR: Interventional Radiology 22 (4) 505 -505 2007年10月
• 胆嚢・胆管癌・膵癌根治術後出血に対し動脈塞栓術を施行した症例の検討

  阿保 大介, 作原 祐介, 長谷川 悠, 藤間 憲幸, 白土 博樹, 清水 匡 IVR: Interventional Radiology 22 (4) 505 -505 2007年10月

共同研究・競争的資金等の研究課題

• 頭頸部癌の個別化医療に向けた腫瘍特性の非侵襲的画像化と人工知能解析の融合

  日本学術振興会：科学研究費助成事業

  研究期間 : 2021年04月 -2024年03月 

  代表者 : 藤間 憲幸, 本間 明宏

   

  本研究は第一段階の目標として、頭頸部扁平上皮癌における腫瘍の細胞増殖能および低酸素領域の非侵襲的な画像化がある。 2021年度において、腫瘍の細胞増殖能は、MRIにおける多b値の拡散強調像から得られた腫瘍の微細構造を反映させた信号データを数学的なモデルを用いて解析し、さらにその情報をamido proton transfer（APT）イメージングより得られた腫瘍のタンパク質代謝情報と掛け合わせることによって高い精度で実現することが出来た。低酸素領域においては、多b値の拡散強調像から得られた腫瘍の微細構造を反映させた信号データおよびArterial Spin Labeling（ASL）より得られた腫瘍の血流情報を反映させたデータを数学的な仮説モデルで解析することによって比較的高い精度で画像化することが可能であった。 本研究の第二段階として、第一段階にて作成した腫瘍の生物学的性状を反映させた画像（腫瘍の細胞増殖能および低酸素領域を反映させた画像）を用いて患者の予後予測のための深層学習モデルを作成するという項目がある。ゆえに、2022年度以降は上述した画像情報を用いて個々の患者の高精度な予後予測を行うための深層学習モデルを作成する予定であるが、2021年度にて深層学習に用いるネットワークの構築を行っている途中である。現状では解析に長い時間がかかる状況であるため、ネットワーク構築の調整を複数回にわたって行い、精度を保ったままの状態で解析時間を短くできるように再構築中である。
• MRIによる頭頸部癌の生物学的特性の画像化と人工知能による予後予測モデル開発

  日本学術振興会：科学研究費助成事業 基盤研究(C)

  研究期間 : 2018年04月 -2021年03月 

  代表者 : 藤間 憲幸, 本間 明宏

   

  頭頸部扁平上皮癌において化学放射線治療に対する感受性を左右する腫瘍の生物学的性状の代表的な項目として腫瘍の細胞増殖能、腫瘍の低酸素領域の含有とその分布、および腫瘍血管の血管透過性（抗がん剤などにおける血管から腫瘍組織内への移行割合）をそれぞれMRIを用いて間接的に画像化させるための撮像シーケンスの調整および画像解析法の開発を行った。腫瘍の細胞増殖能は拡散強調像に非ガウス分布モデルを適合させた撮像を用いて、後処理解析として機械学習法を用いることにより、比較的高い精度で画像化することが可能であった。すなわち、実際の腫瘍増大速度を反映した画像を拡散強調像の後処理解析によって取得することが可能であった。低酸素領域の画像化はArterial spin labeling法によって算出された腫瘍血流の値と、拡散強調像のハイブリッドモデルによる解析値をかけあわせることによって中等度から高度の精度にて検出および画像化することが可能であった。実際の低酸素系のゴールドスタンダートとなる核医学系の撮像によって検出された低酸素領域と、MRIによって間接的に画像化された低酸素領域との比較では、おおよそ7割程度の正診率で低酸素領域を検出可能であることが示された。血管透過性に関しては、diffusion-weighted arterial spin labeling法による直接的な画像化を試みているが、撮像時間が非常に長くなってしまうため、さらなるシーケンス調整が必要であると考えられた。
• MRIを用いた頭頸部腫瘍の治療感受性マップおよび高精度予後予測診断法の開発

  日本学術振興会：科学研究費助成事業 若手研究(B)

  研究期間 : 2015年04月 -2018年03月 

  代表者 : 藤間 憲幸

   

  拡散強調像の撮像法を改変、画像解析法を開発し腫瘍増殖能を反映させたマップを作成した。これは経過観察によって得られた腫瘍の増大速度と比較し、良好な相関が得られた。さらに非侵襲的な灌流強調像であるArterial spin labelingの撮像法を改良し、頭頚部に腫瘍血流を反映させたマップを取得した。これは造影剤を用いた灌流強調像と比較し、良好な相関を得た。最終的に頭頚部扁平上皮癌患者において腫瘍増殖能および血液灌流のマップの数値情報によって患者予後を高精度に予測できることを統計学的に示すことが可能であった。これら2つのマップを掛け合わせ治療反応性を反映させたマップを作成することが出来た。
• O-17水分子・酸素分子MRIによる定量的脳血流・酸素代謝イメージングの開発

  日本学術振興会：科学研究費助成事業 基盤研究(B)

  研究期間 : 2014年04月 -2017年03月 

  代表者 : 工藤 與亮, 真鍋 治, 真鍋 徳子, 佐々木 真理, 加藤 扶美, 藤間 憲幸, 宮本 憲幸, 阿保 大介

   

  MRI信号の理論式を用いて、様々な組織におけるMRI信号強度のシミュレーションを行った。O-17濃度別ファントムのMRI信号値との間に良好な相関が確認され、MRI信号強度からO-17濃度を算出する方法として確立した。健常人ボランティアでのMRI撮像を行い、FSE法を用いて安定したMRI撮像法を確立し、血流量の定量解析を行うアルゴリズムの開発を行った。 O-17酸素分子の製造体制の構築を行い、動物用の吸入装置の設計を行った。小径のO-17濃度別ファントムを作成し、動物用MRIでの撮像実験を行った。O-17水を投与してマーモセットにてMRI撮像を行い、良好な画像コントラストを得た。
• 口腔内扁平上皮癌に対するMR顕微鏡の開発

  日本学術振興会：科学研究費助成事業 基盤研究(C)

  研究期間 : 2013年04月 -2017年03月 

  代表者 : 箕輪 和行, 藤間 憲幸

   

  口腔扁平上皮癌に対してMRI拡散強調像の一つであるQ-space法のパラメータを用いて病理組織学的な情報を非侵襲的に画像化する「MR顕微鏡」を開発することを目的とした。撮像に必要なプログラムを作成し、口腔癌患者から得た病理標本とQ-space法の各パラメータの比較、日常臨床で使用されている画像検索方法とQ-space法の各パラメータの比較を行い、「MR顕微鏡」に使用するQ-space法のどのパラメータが有効かを検討した。解析の結果、我々が作成したQ-space法のパラメータのいくつかは細胞増殖能と相関が示唆され、また、日常使用されている口腔癌の画像診断法との相関もみられた。
• MRIを用いた頭頸部腫瘍における機能情報の非侵襲的画像化に関する研究

  日本学術振興会：科学研究費助成事業 若手研究(B)

  研究期間 : 2013年04月 -2015年03月 

  代表者 : 藤間 憲幸

   

  今回の研究によって、MRIを用いて非侵襲的に頭頸部扁平上皮癌における腫瘍血流（定量値を反映させたマップ）、腫瘍細胞増殖能（間接的な半定量値を反映させたマップ）、腫瘍内の低酸素の度合い（間接的な半定量値を反映させたマップ）をそれぞれ作成した。臨床応用として、治療前、治療途中に撮像されたそれぞれのマップが最終的な治療予後を反映させるかどうかを探索した。治療前と治療途中での腫瘍増殖能の変化率が、特に治療後の予後と強く相関することが判明し、今後も臨床応用に活用することが出来る可能性が示唆された。
• MRIを用いた頭頚部腫瘍における定量的血管支配・活動性マップの開発

  日本学術振興会：科学研究費助成事業 研究活動スタート支援

  研究期間 : 2011年 -2012年 

  代表者 : 藤間 憲幸

   

  動注化学放射線併用療法が予定された頭頸部腫瘍患者を対象として、MRIのArterial spin labeling(ASL)法をベースとした定量的血管支配、活動性マップを開発した。マップの精度検証として、血管支配域は選択的動注CTや選択的血管造影所見と対比を行い、活動性に関しては、定量的に算出した腫瘍血流を疑似的に活動性の指標とし、FDG-PETや、血管造影での腫瘍濃染の程度、経過観察の情報から検証を行い、いずれも開発されたマップの良好な精度が確認された。