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Last Updated :2024/10/21

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Master

Affiliation (Master)

  • Faculty of Medicine　Global Center for BiomedicalScience and Engineering

Affiliation (Master)

  • Faculty of Medicine　Global Center for BiomedicalScience and Engineering

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Profile and Settings

Degree

  • MD (MBBS)（University of Medicine (2), Yangon, Myanmar）
  • PhD（Hokkaido University, Sapporo, Japan）

Profile and Settings

  • Name (Japanese)

    Tha

  • Name (Kana)

    Khin Khin

  • Name

    201301056270817153

Alternate Names

Achievement

Research Interests

  • Electrical conductivity   Diffusion imaging   Radiomics   Neuroradiology   Magnetic resonance imaging   Radiology   

Research Areas

  • Life sciences / Neuroanatomy and physiology
  • Life sciences / Basic brain sciences
  • Life sciences / Radiology

Research Experience

  • 2020/04 - Today Hokkaido University Faculty of Medicine Global Center for Biomedical Science and Engineering Associate professor

Committee Memberships

  • 2024/05 - Today   International Society of Magnetic Resonance in Medicine   Education committee
  • 2020/09 - Today   Japanese Society of Magnetic Resonance in Medicine   Planning Committee
  • 2020/09 - Today   Japanese Society of Magnetic Resonance in Medicine   Diversity Committee
  • 2021/05 -2024/05   International Society for Magnetic Resonance in Medicine   Annual Meeting Program Committee
  • 2018/06 -2021/05   International Society for Magnetic Resonance Imaging   Safety committee

Awards

  • 2022/05 Asian Society of Magnetic Resonance in Medicine Contribution award
     
    受賞者: Khin Khin Tha
  • 2021/09 Japanese Society of Magnetic Resonance in Medicine Outstanding presentation
     
    受賞者: Khin Khin Tha;Ulrich Katscher;Xinnan Li;Hiroyuki Hamaguchi;Hideki Hyodoh
  • 2021/08 Hokkaido University School of Medicine Excellent Teacher Award
     
    受賞者: Khin Khin Tha
  • 2020/09 Hokkaido University School of Medicine Excellent Teacher Award
  • 2020/04 Japan Radiological Society Excellent Reviewer Award
  • 2018/12 Hokkaido University Global Networking Award
  • 2018/08 Journal of Magnetic Resonance Imaging JMRI Reviewer Award (Reviewer with Distinction)
  • 2018/07 Hokkaido University School of Medicine Excellent Teacher
  • 2018/03 The 12th Asian-Oceanian Congress of Neuroradiology Guerbet Scientific Award (Cum Laude)
     Recent advances and new trends in glioma imaging 
    受賞者: Tha KK
  • 2017/07 Hokkaido University School of Medicine Excellent Teacher
  • 2014/03 Japan Society of Neuroradiology Outstanding poster award, third prize (Scientific presentation)
     Noninvasive evaluation of electrical conductivity of the brain tumors by MRI 
    受賞者: Khin Khin Tha
  • 2012/10 The 40th Japanese Society for Magnetic Resonance in Medicine Presidential award
     Laterality of the corticospinal tract and influence of handedness: a diffusion tensor imaging observation 
    受賞者: Khin Khin Tha
  • 2011/05 The International Society for Magnetic Resonance in Medicine Quiz winner
     
    受賞者: Khin Khin Tha
  • 2010/09 The Japanese Society for Magnetic Resonance in Medicine Presidential award
     Diffusion Tensor Imaging Characteristics of Normal Human Cervical Spinal Cord at 3T 
    受賞者: Khin Khin Tha
  • 2010/02 The Japanese Society of Neuroradiology Kato prize
     Microstructural white matter abnormalities of multiple system atrophy: in vivo topographic illustration by using diffusion-tensor MR imaging. 
    受賞者: Khin Khin Tha
  • 2006/06 Department of Radiation Medicine (Alumni), Hokkaido University Graduate School of Medicine Wakabayashi Memorial Award
     Early detection of global cerebral anoxia: Improved accuracy by high b-value diffusion-weighted imaging with long echo time 
    受賞者: Khin Khin Tha
  • 2006/03 Symposium Neuroradiologicum Travel Fellowship Award
     High b-value diffusion-weighted imaging of the brain: advantages and pitfalls 
    受賞者: Khin Khin Tha
  • 2006/02 The Japanese Society of Neuroradiology Best poster award
     
    受賞者: Khin Khin Tha
  • 2005/12 The Radiological Society of North America Cum Laude
     Imaging spectrum of hyperintense cerebrospinal fluid on fluid-attenuated inversion recovery images of the brain 
    受賞者: Khin Khin Tha

Published Papers

  • Daisuke Ukeba, Yoko Ishikawa, Katsuhisa Yamada, Takashi Ohnishi, Hiroyuki Tachi, Khin Khin Tha, Norimasa Iwasaki, Hideki Sudo
    Cells 13 (11) 2024/06/05 
    Although discectomy is commonly performed for lumbar intervertebral disc (IVD) herniation, the capacity for tissue repair after surgery is limited, resulting in residual lower back pain, recurrence of IVD herniation, and progression of IVD degeneration. Cell-based therapies, as one-step procedures, are desirable for enhancing IVD repair. This study aimed to investigate the therapeutic efficacy of a combination of newly developed ultra-purified alginate (UPAL) gel and bone marrow aspirate concentrate (BMAC) implantation for IVD repair after discectomy. Prior to an in vivo study, the cell concentration abilities of three commercially available preparation kits for creating the BMAC were compared by measuring the number of bone marrow mesenchymal stem cells harvested from the bone marrow of rabbits. Subsequently, canine-derived BMAC was tested in a canine model using a kit which had the highest concentration rate. At 24 weeks after implantation, we evaluated the changes in the magnetic resonance imaging (MRI) signals as well as histological degeneration grade and immunohistochemical analysis results for type II and type I collagen-positive cells in the treated IVDs. In all quantitative evaluations, such as MRI and histological and immunohistochemical analyses of IVD degeneration, BMAC-UPAL implantation significantly suppressed the progression of IVD degeneration compared to discectomy and UPAL alone. This preclinical proof-of-concept study demonstrated the potential efficacy of BMAC-UPAL gel as a therapeutic strategy for implementation after discectomy, which was superior to UPAL and discectomy alone in terms of tissue repair and regenerative potential.
  • Masahito Kawabori, Satoshi Kuroda, Hideo Shichinohe, Kaoru Kahata, Souichi Shiratori, Satoshi Ikeda, Taisuke Harada, Kenji Hirata, Khin Khin Tha, Masato Aragaki, Shunsuke Terasaka, Yoichi M Ito, Naoki Nishimoto, Shunsuke Ohnishi, Ichiro Yabe, Kohsuke Kudo, Kiyohiro Houkin, Miki Fujimura
    Med (New York, N.Y.) 2024/03/18 
    BACKGROUND: Ischemic stroke is one of the leading causes of death and neurological disability worldwide, and stem cell therapy is highly expected to reverse the sequelae. This phase 1/2, first-in-human study evaluated the safety, feasibility, and monitoring of an intracerebral-transplanted magnetic resonance imaging (MRI)-trackable autologous bone marrow stromal cell (HUNS001-01) for patients with subacute ischemic stroke. METHODS: The study included adults with severe disability due to ischemic stroke. HUNS001-01 cultured with human platelet lysates and labeled with superparamagnetic iron oxide was stereotactically transplanted into the peri-infarct area 47-64 days after ischemic stroke onset (dose: 2 or 5 × 107 cells). Neurological and radiographic evaluations were performed throughout 1 year after cell transplantation. The trial was registered at UMIN Clinical Trial Registry (number UMIN000026130). FINDINGS: All seven patients who met the inclusion criteria successfully achieved cell expansion, underwent intracerebral transplantation, and completed 1 year of follow-up. No product-related adverse events were observed. The median National Institutes of Health Stroke Scale and modified Rankin scale scores before transplantation were 13 and 4, which showed improvements of 1-8 and 0-2, respectively. Cell tracking proved that the engrafted cells migrated toward the infarction border area 1-6 months after transplantation, and the quantitative susceptibility mapping revealed that cell signals at the migrated area constantly increased throughout the follow-up period up to 34% of that of the initial transplanted site. CONCLUSIONS: Intracerebral transplantation of HUNS001-01 was safe and well tolerated. Cell tracking shed light on the therapeutic mechanisms of intracerebral transplantation. FUNDING: This work was supported by the Japan Agency for Medical Research and Development (AMED; JP17bk0104045 and JP20bk0104011).
  • Maho Kitagawa, Kagari Abiko, Sulaiman Sheriff, Andrew Maudsley, Xinnan Li, Daisuke Sawamura, Sinyeob Ahn, Khin Tha
    Metabolites 2023/12/27 [Refereed]
  • Junya Matsumoto, Masaki Fukunaga, Kenichiro Miura, Kiyotaka Nemoto, Naohiro Okada, Naoki Hashimoto, Kentaro Morita, Daisuke Koshiyama, Kazutaka Ohi, Tsutomu Takahashi, Michihiko Koeda, Hidenaga Yamamori, Michiko Fujimoto, Yuka Yasuda, Satsuki Ito, Ryuichi Yamazaki, Naomi Hasegawa, Hisashi Narita, Satoshi Yokoyama, Ryo Mishima, Jun Miyata, Yuko Kobayashi, Daiki Sasabayashi, Kenichiro Harada, Maeri Yamamoto, Yoji Hirano, Takashi Itahashi, Masahito Nakataki, Ryu-Ichiro Hashimoto, Khin K Tha, Shinsuke Koike, Toshio Matsubara, Go Okada, Reiji Yoshimura, Osamu Abe, Theo G M van Erp, Jessica A Turner, Neda Jahanshad, Paul M Thompson, Toshiaki Onitsuka, Yoshiyuki Watanabe, Koji Matsuo, Hidenori Yamasue, Yasumasa Okamoto, Michio Suzuki, Norio Ozaki, Kiyoto Kasai, Ryota Hashimoto
    Molecular psychiatry 28 (11) 4915 - 4923 2023/11 
    According to the operational diagnostic criteria, psychiatric disorders such as schizophrenia (SZ), bipolar disorder (BD), major depressive disorder (MDD), and autism spectrum disorder (ASD) are classified based on symptoms. While its cluster of symptoms defines each of these psychiatric disorders, there is also an overlap in symptoms between the disorders. We hypothesized that there are also similarities and differences in cortical structural neuroimaging features among these psychiatric disorders. T1-weighted magnetic resonance imaging scans were performed for 5,549 subjects recruited from 14 sites. Effect sizes were determined using a linear regression model within each protocol, and these effect sizes were meta-analyzed. The similarity of the differences in cortical thickness and surface area of each disorder group was calculated using cosine similarity, which was calculated from the effect sizes of each cortical regions. The thinnest cortex was found in SZ, followed by BD and MDD. The cosine similarity values between disorders were 0.943 for SZ and BD, 0.959 for SZ and MDD, and 0.943 for BD and MDD, which indicated that a common pattern of cortical thickness alterations was found among SZ, BD, and MDD. Additionally, a generally smaller cortical surface area was found in SZ and MDD than in BD, and the effect was larger in SZ. The cosine similarity values between disorders were 0.945 for SZ and MDD, 0.867 for SZ and ASD, and 0.811 for MDD and ASD, which indicated a common pattern of cortical surface area alterations among SZ, MDD, and ASD. Patterns of alterations in cortical thickness and surface area were revealed in the four major psychiatric disorders. To our knowledge, this is the first report of a cross-disorder analysis conducted on four major psychiatric disorders. Cross-disorder brain imaging research can help to advance our understanding of the pathogenesis of psychiatric disorders and common symptoms.
  • Khin Khin Tha
    European radiology 33 (11) 8002 - 8004 2023/11
  • Naohiro Okada, Masaki Fukunaga, Kenichiro Miura, Kiyotaka Nemoto, Junya Matsumoto, Naoki Hashimoto, Masahiro Kiyota, Kentaro Morita, Daisuke Koshiyama, Kazutaka Ohi, Tsutomu Takahashi, Michihiko Koeda, Hidenaga Yamamori, Michiko Fujimoto, Yuka Yasuda, Naomi Hasegawa, Hisashi Narita, Satoshi Yokoyama, Ryo Mishima, Takahiko Kawashima, Yuko Kobayashi, Daiki Sasabayashi, Kenichiro Harada, Maeri Yamamoto, Yoji Hirano, Takashi Itahashi, Masahito Nakataki, Ryu-Ichiro Hashimoto, Khin K Tha, Shinsuke Koike, Toshio Matsubara, Go Okada, Theo G M van Erp, Neda Jahanshad, Reiji Yoshimura, Osamu Abe, Toshiaki Onitsuka, Yoshiyuki Watanabe, Koji Matsuo, Hidenori Yamasue, Yasumasa Okamoto, Michio Suzuki, Jessica A Turner, Paul M Thompson, Norio Ozaki, Kiyoto Kasai, Ryota Hashimoto
    Molecular psychiatry 2023/08/04 
    Differential diagnosis is sometimes difficult in practical psychiatric settings, in terms of using the current diagnostic system based on presenting symptoms and signs. The creation of a novel diagnostic system using objective biomarkers is expected to take place. Neuroimaging studies and others reported that subcortical brain structures are the hubs for various psycho-behavioral functions, while there are so far no neuroimaging data-driven clinical criteria overcoming limitations of the current diagnostic system, which would reflect cognitive/social functioning. Prior to the main analysis, we conducted a large-scale multisite study of subcortical volumetric and lateralization alterations in schizophrenia, bipolar disorder, major depressive disorder, and autism spectrum disorder using T1-weighted images of 5604 subjects (3078 controls and 2526 patients). We demonstrated larger lateral ventricles volume in schizophrenia, bipolar disorder, and major depressive disorder, smaller hippocampus volume in schizophrenia and bipolar disorder, and schizophrenia-specific smaller amygdala, thalamus, and accumbens volumes and larger caudate, putamen, and pallidum volumes. In addition, we observed a leftward alteration of lateralization for pallidum volume specifically in schizophrenia. Moreover, as our main objective, we clustered the 5,604 subjects based on subcortical volumes, and explored whether data-driven clustering results can explain cognitive/social functioning in the subcohorts. We showed a four-biotype classification, namely extremely (Brain Biotype [BB] 1) and moderately smaller limbic regions (BB2), larger basal ganglia (BB3), and normal volumes (BB4), being associated with cognitive/social functioning. Specifically, BB1 and BB2-3 were associated with severe and mild cognitive/social impairment, respectively, while BB4 was characterized by normal cognitive/social functioning. Our results may lead to the future creation of novel biological data-driven psychiatric diagnostic criteria, which may be expected to be useful for prediction or therapeutic selection.
  • Hiroyuki Hamaguchi, Maho Kitagawa, Daiki Sakamoto, Ulrich Katscher, Hideki Sudo, Katsuhisa Yamada, Kohsuke Kudo, Khin Khin Tha
    Tomography (Ann Arbor, Mich.) 9 (3) 1029 - 1040 2023/05/16 
    Whether diurnal variation exists in quantitative MRI indices such as the T1rho relaxation time (T1ρ) of the intervertebral disc (IVD) is yet to be explored. This prospective study aimed to evaluate the diurnal variation in T1ρ, apparent diffusion coefficient (ADC), and electrical conductivity (σ) of lumbar IVD and its relationship with other MRI or clinical indices. Lumbar spine MRI, including T1ρ imaging, diffusion-weighted imaging (DWI), and electric properties tomography (EPT), was conducted on 17 sedentary workers twice (morning and evening) on the same day. The T1ρ, ADC, and σ of IVD were compared between the time points. Their diurnal variation, if any, was tested for correlation with age, body mass index (BMI), IVD level, Pfirrmann grade, scan interval, and diurnal variation in IVD height index. The results showed a significant decrease in T1ρ and ADC and a significant increase in the σ of IVD in the evening. T1ρ variation had a weak correlation with age and scan interval, and ADC variation with scan interval. Diurnal variation exists for the T1ρ, ADC, and σ of lumbar IVD, which should be accounted for in image interpretation. This variation is thought to be due to diurnal variations in intradiscal water, proteoglycan, and sodium ion concentration.
  • Kodai Sakiyama, Nobuya Abe, Yuichiro Fujieda, Khin K Tha, Hisashi Narita, Kohei Karino, Masatoshi Kanda, Michihito Kono, Masaru Kato, Tatsuya Atsumi
    Cerebral cortex (New York, N.Y. : 1991) 33 (13) 8342 - 8351 2023/04/01 
    Aberrant functional connectivity (FC) of the brain regions, evaluated by functional magnetic resonance imaging (fMRI), affects clinical courses in inflammatory arthritis (IA). The static analysis methods would be simplistic to estimate the whole picture of resting-state brain function because blood oxygen level-dependent (BOLD) signals fluctuate over time. The effects of FC dynamics on clinical course are unknown in IA. Therefore, we aimed to evaluate dynamic FC for therapeutic responsiveness to biologics in IA patients. We analyzed resting-state fMRI data of 64 IA patients in 2 cohorts. Dynamic FC was derived as a correlation coefficient of the windowed BOLD signal time series. We determined representative whole-brain dynamic FC patterns by k-means++ cluster analysis, leading to 4 distinct clusters. In the first cohort, occurrence probability of the distinct cluster was associated with favorable therapeutic response in disease activity and patients' global assessment, which was validated by the second cohort. The whole-brain FC of the distinct cluster indicated significantly increased corticocortical connectivity, and probabilistically decreased after therapy in treatment-effective patients compared with -ineffective patients. Taken together, frequent emergence of corticocortical connections was associated with clinical outcomes in IA. The coherence of corticocortical interactions might affect pain modulation, possibly relevant to therapeutic satisfaction.
  • Hideki Sudo, Takashi Miyakoshi, Yudai Watanabe, Yoichi M Ito, Kaoru Kahata, Khin Khin Tha, Nozomi Yokota, Hiroe Kato, Tomoko Terada, Norimasa Iwasaki, Teruyo Arato, Norihiro Sato, Toshiyuki Isoe
    BMJ open 13 (2) e065476  2023/02/02 
    INTRODUCTION: In patients with combined lumbar spinal canal stenosis (LSCS), a herniated intervertebral disc (IVD) that compresses the dura mater and nerve roots is surgically treated with discectomy after laminoplasty. However, defects in the IVD after discectomy may lead to inadequate tissue healing and predispose patients to the development of IVD degeneration. Ultrapurified stem cells (rapidly expanding clones (RECs)), combined with an in situ-forming bioresorbable gel (dMD-001), have been developed to fill IVD defects and prevent IVD degeneration after discectomy. We aim to investigate the safety and efficacy of a new treatment method in which a combination of REC and dMD-001 is implanted into the IVD of patients with combined LSCS. METHODS AND ANALYSIS: This is a multicentre, prospective, double-blind randomised controlled trial. Forty-five participants aged 20-75 years diagnosed with combined LSCS will be assessed for eligibility. After performing laminoplasty and discectomy, participants will be randomised 1:1:1 into the combination of REC and dMD-001 (REC-dMD-001) group, the dMD-001 group or the laminoplasty and discectomy alone (control) group. The primary outcomes of the trial will be the safety and effectiveness of the procedure. The effectiveness will be assessed using visual analogue scale scores of back pain and leg pain as well as MRI-based estimations of morphological and compositional quality of the IVD tissue. Secondary outcomes will include self-assessed clinical scores and other MRI-based estimations of compositional quality of the IVD tissue. All evaluations will be performed at baseline and at 1, 4, 12, 24 and 48 weeks after surgery. ETHICS AND DISSEMINATION: This study was approved by the ethics committees of the institutions involved. We plan to conduct dissemination of the outcome data by presenting our data at national and international conferences, as well as through formal publication in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: jRCT2013210076.
  • 肝細胞癌陽子線治療効果予測におけるADC値指標の検討
    藤田 祥博, 加藤 徳雄, 打浪 雄介, 田口 大志, 西岡 健太郎, 森 崇, 安田 耕一, 小泉 富基, 大塚 愛美, 高尾 聖心, 田村 昌也, Sutherland Kenneth, Khin Khin Tha, 伊藤 陽一, 青山 英史
    Japanese Journal of Radiology (公社)日本医学放射線学会 41 (Suppl.) 10 - 10 1867-1071 2023/02
  • Nobuya Abe, Masato Tarumi, Yuichiro Fujieda, Nobuhiko Takahashi, Kohei Karino, Mona Uchida, Michihito Kono, Yuki Tanaka, Rie Hasebe, Masaru Kato, Olga Amengual, Yoshiyuki Arinuma, Kenji Oku, Wakiro Sato, Khin Khin Tha, Miwako Yamasaki, Masahiko Watanabe, Tatsuya Atsumi, Masaaki Murakami
    Annals of the rheumatic diseases 81 (11) 1564 - 1575 2022/07/11 
    OBJECTIVES: The central nervous system disorder in systemic lupus erythematosus (SLE), called neuropsychiatric lupus (NPSLE), is one of the most severe phenotypes with various clinical symptoms, including mood disorder, psychosis and delirium as diffuse neuropsychological manifestations (dNPSLE). Although stress is one of the aggravating factors for neuropsychiatric symptoms, its role in the pathogenesis of dNPSLE remains to be elucidated. We aimed to investigate stress effects on the neuropsychiatric pathophysiology in SLE using lupus-prone mice and patients' data. METHODS: Sleep disturbance stress (SDS) for 2 weeks was placed on 6-8-week-old female MRL/lpr and control mice. Behavioural phenotyping, histopathological analyses and gene and protein expression analyses were performed to assess SDS-induced neuroimmunological alterations. We also evaluated cytokines of the cerebrospinal fluid and brain regional volumes in patients with dNPSLE and patients with non-dNPSLE. RESULTS: SDS-subjected MRL/lpr mice exhibited less anxiety-like behaviour, whereas stressed control mice showed increased anxiety. Furthermore, stress strongly activated the medial prefrontal cortex (mPFC) in SDS-subjected MRL/lpr. A transcriptome analysis of the PFC revealed the upregulation of microglial activation-related genes, including Il12b. We confirmed that stress-induced microglial activation and the upregulation of interleukin (IL) 12/23p40 proteins and increased dendritic spines in the mPFC of stressed MRL/lpr mice. IL-12/23p40 neutralisation and tyrosine kinase 2 inhibition mitigated the stress-induced neuropsychiatric phenotypes of MRL/lpr mice. We also found a higher level of cerebrospinal fluid IL-12/23p40 and more atrophy in the mPFC of patients with dNPSLE than those with non-dNPSLE. CONCLUSIONS: The microglial IL-12/23 axis in the mPFC might be associated with the pathogenesis and a promising therapeutic target for dNPSLE.
  • Ryota Sato, Kohsuke Kudo, Niki Udo, Masaaki Matsushima, Ichiro Yabe, Akinori Yamaguchi, Khin Khin Tha, Makoto Sasaki, Masafumi Harada, Noriyuki Matsukawa, Tomoki Amemiya, Yasuo Kawata, Yoshitaka Bito, Hisaaki Ochi, Toru Shirai
    European radiology 32 (7) 4479 - 4488 2022/07 
    OBJECTIVES: Voxel-based morphometry (VBM) is widely used to quantify the progression of Alzheimer's disease (AD), but improvement is still needed for accurate early diagnosis. We evaluated the feasibility of a novel diagnosis index for early diagnosis of AD based on quantitative susceptibility mapping (QSM) and VBM. METHODS: Thirty-seven patients with AD, 24 patients with mild cognitive impairment (MCI) due to AD, and 36 cognitively normal (NC) subjects from four centers were included. A hybrid sequence was performed by using 3-T MRI with a 3D multi-echo GRE sequence to obtain both a T1-weighted image for VBM and phase images for QSM. The index was calculated from specific voxels in QSM and VBM images by using a linear support vector machine. The method of voxel extraction was optimized to maximize diagnostic accuracy, and the optimized index was compared with the conventional VBM-based index using receiver operating characteristic analysis. RESULTS: The index was optimal when voxels were extracted as increased susceptibility (AD > NC) in the parietal lobe and decreased gray matter volume (AD < NC) in the limbic system. The optimized proposed index showed excellent performance for discrimination between AD and NC (AUC = 0.94, p = 1.1 × 10-10) and good performance for MCI and NC (AUC = 0.87, p = 1.8 × 10-6), but poor performance for AD and MCI (AUC = 0.68, p = 0.018). Compared with the conventional index, AUCs were improved for all cases, especially for MCI and NC (p < 0.05). CONCLUSIONS: In this preliminary study, the proposed index based on QSM and VBM improved the diagnostic performance between MCI and NC groups compared with the VBM-based index. KEY POINTS: • We developed a novel diagnostic index for Alzheimer's disease based on quantitative susceptibility mapping (QSM) and voxel-based morphometry (VBM). • QSM and VBM images can be acquired simultaneously in a single sequence with little increasing scan time. • In this preliminary study, the proposed diagnostic index improved the discriminative performance between mild cognitive impairment and normal control groups compared with the conventional VBM-based index.
  • Xinnan Li, Kagari Abiko, Sulaiman Sheriff, Andrew A Maudsley, Yuta Urushibata, Sinyeob Ahn, Khin Khin Tha
    Metabolites 12 (6) 2022/06/14 
    This prospective study aimed to evaluate the variation in magnetic resonance spectroscopic imaging (MRSI)-observed brain metabolite concentrations according to anatomical location, sex, and age, and the relationships among regional metabolite distributions, using short echo time (TE) whole-brain MRSI (WB-MRSI). Thirty-eight healthy participants underwent short TE WB-MRSI. The major metabolite ratios, i.e., N-acetyl aspartate (NAA)/creatine (Cr), choline (Cho)/Cr, glutamate + glutamine (Glx)/Cr, and myoinositol (mI)/Cr, were calculated voxel-by-voxel. Their variations according to anatomical regions, sex, and age, and their relationship to each other were evaluated by using repeated-measures analysis of variance, t-tests, and Pearson's product-moment correlation analyses. All four metabolite ratios exhibited widespread regional variation across the cerebral hemispheres (corrected p < 0.05). Laterality between the two sides and sex-related variation were also shown (p < 0.05). In several regions, NAA/Cr and Glx/Cr decreased and mI/Cr increased with age (corrected p < 0.05). There was a moderate positive correlation between NAA/Cr and mI/Cr in the insular lobe and thalamus and between Glx/Cr and mI/Cr in the parietal lobe (r ≥ 0.348, corrected p ≤ 0.025). These observations demand age- and sex- specific regional reference values in interpreting these metabolites, and they may facilitate the understanding of glial-neuronal interactions in maintaining homeostasis.
  • Nobuya Abe, Yuichiro Fujieda, Khin K Tha, Hisashi Narita, Kuniyuki Aso, Kohei Karino, Masatoshi Kanda, Michihito Kono, Masaru Kato, Olga Amengual, Tatsuya Atsumi
    Seminars in arthritis and rheumatism 55 151994 - 151994 2022/03/15 
    BACKGROUND: Brain activity is reported to be associated with individual pain susceptibility and inflammatory status, possibly contributing to disease activity assessment in inflammatory arthritis (IA) including rheumatoid arthritis (RA) and spondyloarthritis (SpA). However, what alteration of brain function associated with disease activity and therapeutic effectiveness in IA remains unclear. We aimed to identify the alterations of brain functional connectivity (FC) shared in both RA and SpA, and evaluate its relationship to anti-rheumatic treatment response using functional magnetic resonance imaging (MRI). PATIENTS AND METHODS: Structural and resting-state functional MRI data were acquired from patients with IA, patients with osteoarthritis (OA) and heathy controls (HCs). Two datasets were adopted to derive (51 IA, 56 OA, and 17 HCs) and validate (31 IA) the observations. 33 IA patients in the derivation dataset and all the patients in validation dataset required biological treatment and were clinically evaluated before and after therapy. Via whole-brain pair-wise FC analyses, we analyzed IA-specific FC measures relevant to therapeutic response to biologics. RESULTS: The value of FC between left insular cortex (IC) and anterior cingulate cortex (ACC) was significantly low in IA patients compared with OA patients and HCs. We demonstrated that the FC between left anterior long insular gyrus as a subdivision of IC and ACC was significantly associated with therapeutic response to biologics regarding the improvement of patients' global assessment (PGA) in both derivation and validation datasets. CONCLUSION: Disease-specific resting-state FC provides a means to assess the therapeutic improvement of PGA and would be a clinical decision-making tool with predictability for treatment response in both RA and SpA.
  • Soichiro Takamiya, Masahito Kawabori, Kazuyoshi Yamazaki, Sho Yamaguchi, Aki Tanimori, Koji Yamamoto, Shunsuke Ohnishi, Toshitaka Seki, Kotaro Konno, Khin Khin Tha, Daigo Hashimoto, Masahiko Watanabe, Kiyohiro Houkin, Miki Fujimura
    PloS one 17 (7) e0270606  2022 
    Spinal cord injury (SCI) is often accompanied by gastrointestinal dysfunction due to the disconnection of the spinal autonomic nervous system. Gastrointestinal dysfunction reportedly upregulates intestinal permeability, leading to bacterial translocation of the gut microbiome to the systemic circulation, which further activates systemic inflammation, exacerbating neuronal damage. Mesenchymal stem cells (MSC) reportedly ameliorate SCI. Here, we aimed to investigate their effect on the associated gastrointestinal dysfunction. Human amnion-derived MSC (AMSCs) were intravenously transplanted one day after a rat model of midthoracic SCI. Biodistribution of transplanted cells, behavioral assessment, and histological evaluations of the spinal cord and intestine were conducted to elucidate the therapeutic effect of AMSCs. Bacterial translocation of the gut microbiome was examined by in situ hybridization and bacterial culture of the liver. Systemic inflammations were examined by blood cytokines, infiltrating immune cells in the spinal cord, and the size of the peripheral immune tissue. AMSCs released various neurotrophic factors and were mainly distributed in the liver and lung after transplantation. AMSC-transplanted animals showed smaller spinal damage and better neurological recovery with preserved neuronal tract. AMSCs transplantation ameliorated intestinal dysfunction both morphologically and functionally, which prevented translocation of the gut microbiome to the systemic circulation. Systemic inflammations were decreased in animals receiving AMSCs in the chronic phase. Intravenous AMSC administration during the acute phase of SCI rescues both spinal damage and intestinal dysfunction. Reducing bacterial translocation may contribute to decreasing systemic inflammation.
  • Xinnan Li, Daisuke Sawamura, Hiroyuki Hamaguchi, Yuta Urushibata, Thorsten Feiweier, Keita Ogawa, Khin Khin Tha
    Tomography (Ann Arbor, Mich.) 8 (1) 33 - 44 2022/01/01 
    Cognitive training-induced neuroplastic brain changes have been reported. This prospective study evaluated whether microscopic fractional anisotropy (μFA) derived from double diffusion encoding (DDE) MRI could detect brain changes following a 4 week cognitive training. Twenty-nine healthy volunteers were recruited and randomly assigned into the training (n = 21) and control (n = 8) groups. Both groups underwent brain MRI including DDE MRI and 3D-T1-weighted imaging twice at an interval of 4-6 weeks, during which the former underwent the training. The training consisted of hour-long dual N-back and attention network tasks conducted five days per week. Training and time-related changes of DDE MRI indices (μFA, fractional anisotropy (FA), and mean diffusivity (MD)) and the gray and white matter volume were evaluated using mixed-design analysis of variance. In addition, any significant imaging indices were tested for correlation with cognitive training-induced task performance changes, using partial correlation analyses. μFA in the left middle frontal gyrus decreased upon the training (53 voxels, uncorrected p < 0.001), which correlated moderately with response time changes in the orienting component of attention (r = -0.521, uncorrected p = 0.032). No significant training and time-related changes were observed for other imaging indices. Thus, μFA can become a sensitive index to detect cognitive training-induced neuroplastic changes.
  • Jeremy D Collins, Howard Rowley, Tim Leiner, Scott Reeder, Maureen Hood, Ilona Dekkers, Khin Tha, Vikas Gulani, Emre Kopanoglu
    Journal of magnetic resonance imaging : JMRI 55 (5) 1322 - 1339 2021/12/20 
    The COVID-19 pandemic highlighted the challenges delivering face-to-face patient care across healthcare systems. In particular the COVID-19 pandemic challenged the imaging community to provide timely access to essential diagnostic imaging modalities while ensuring appropriate safeguards were in place for both patients and personnel. With increasing vaccine availability and greater prevalence of vaccination in communities worldwide we are finally emerging on the other side of the COVID-19 pandemic. As we learned from our institutional and healthcare system responses to the pandemic, maintaining timely access to MR imaging is essential. Radiologists and other imaging providers partnered with their referring providers to ensure that timely access to advanced MR imaging was maintained. On behalf of the International Magnetic Resonance in Medicine (ISMRM) Safety Committee, this white paper is intended to serve as a guide for radiology departments, imaging centers, and other imaging specialists who perform MR imaging to refer to as we prepare for the next pandemic. Lessons learned including strategies to triage and prioritize MR imaging research during a pandemic are discussed. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 5.
  • Katsuhisa Yamada, Maeda Kenichiro, Yoichi M Ito, Fujio Inage, Toshiyuki Isoe, Nozomi Yokota, Osamu Sugita, Norihiro Sato, Khin Khin Tha, Norimasa Iwasaki, Teruyo Arato, Hideki Sudo
    Contemporary clinical trials communications 23 100805 - 100805 2021/09 
    Herniated nucleus pulposus (NP), one of the most common diseases of the spine, is surgically treated by removing the sequestered NP. However, intervertebral disc (IVD) defects may remain after discectomy, leading to inadequate tissue healing and predisposing patients to IVD degeneration. An acellular, bioresorbable, ultra-purified alginate (UPAL) gel (dMD-001) implantation system can be used to fill any IVD defects in order to prevent IVD degeneration after discectomy. This first-in-human pilot study aims to determine the feasibility, safety, and perceived patient response to a combined treatment involving discectomy and UPAL gel implantation for herniated NP. We designed a one-arm, double-centre, open-label, pilot trial. The study started in November 2018 and will run until a sample of 40 suitable participants is established. Patients aged 20-49 years, diagnosed with isolated lumbar IVD herniation and scheduled for discectomy represent suitable candidates. All eligible participants who provide informed consent undergo standard discectomy followed by UPAL gel implantation. The primary outcomes of the trial will be the feasibility and safety of the procedure. Secondary outcomes will include self-assessed clinical scores and magnetic resonance imaging-based measures of morphological and compositional quality of the IVD tissue. Initial outcomes will be published at 24 weeks. Analysis of feasibility and safety will be performed using descriptive statistics. Both intention-to-treat and per-protocol analyses of treatment trends of effectiveness will be conducted.
  • Tha KK, Kikuchi Y, Ishizaka K, Kamiyama T, Yoneyama M, Katscher U
    Journal of Magnetic Resonance Imaging 54 (5) 1689 - 1691 2021/05 [Refereed][Not invited]
  • 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 2020/10 [Refereed][Not invited]
     
    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 J. Magn. Reson. Imaging 2020;52:1187-1196.
  • Yukie Shimizu, Kohsuke Kudo, Hiroyuki Kameda, Taisuke Harada, Noriyuki Fujima, Takuya Toyonaga, Khin Khin Tha, Hiroki Shirato
    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 19 (3) 227 - 234 2020/08/03 [Refereed][Not invited]
     
    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.
  • Nils Hampe, Ulrich Katscher, Cornelis A T van den Berg, Khin Khin Tha, Stefano Mandija
    Physics in medicine and biology 65 (13) 135001 - 135001 2020/06/26 [Refereed][Not invited]
     
    To investigate deep learning electrical properties tomography (EPT) for application on different simulated and in-vivo datasets, including pathologies for brain conductivity reconstructions, 3D patch-based convolutional neural networks were trained to predict conductivity maps from B 1 transceive phase data. To compare the performance of DL-EPT networks on different datasets, three datasets were used throughout this work, one from simulations and two from in-vivo measurements from healthy volunteers and patients with brain lesions, respectively. At first, networks trained on simulations were tested on all datasets with different levels of homogeneous Gaussian noise introduced in training and testing. Secondly, to investigate potential robustness towards systematical differences between simulated and measured phase maps, in-vivo data with conductivity labels from conventional EPT were used for training. High quality conductivity reconstructions from networks trained on simulations with and without noise confirm the potential of deep learning for EPT. However, when this network is used for in-vivo reconstructions, measurement related artifacts affect the quality of conductivity maps. Training DL-EPT networks using conductivity labels from conventional EPT improves the quality of the results. Networks trained on realistic simulations yield reconstruction artifacts when applied to in-vivo data. Training with realistic phase data and conductivity labels from conventional EPT allows for reducing these artifacts.
  • Khin Khin Tha
    Journal of magnetic resonance imaging : JMRI 51 (6) 1844 - 1845 1053-1807 2020/06 [Refereed][Invited]
  • Noriyuki Fujima, Hiroyuki Kameda, Yukie Shimizu, Taisuke Harada, Khin Khin Tha, Masami Yoneyama, Kohsuke Kudo
    Magnetic resonance imaging 69 81 - 87 2020/06 [Refereed][Not invited]
     
    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.
  • Ken Kazumata, Kikutaro Tokairin, Masaki Ito, Haruto Uchino, Taku Sugiyama, Masahito Kawabori, Toshiya Osanai, Khin Khin Tha, Kiyohiro Houkin
    Journal of neurosurgery 134 (3) 1 - 10 2020/04/03 [Refereed][Not invited]
     
    OBJECTIVE: The microstructural integrity of gray and white matter is decreased in adult moyamoya disease, suggesting covert ischemic injury as a mechanism of cognitive dysfunction. Establishing a microstructural brain imaging marker is critical for monitoring cognitive outcomes following surgical interventions. The authors of the present study determined the pathophysiological basis of altered microstructural brain injury in relation to advanced arterial occlusion, cerebral hypoperfusion, and cognitive function. METHODS: The authors examined 58 patients without apparent brain lesions and 30 healthy controls by using structural MRI, as well as diffusion tensor imaging (DTI). Arterial occlusion in each hemisphere was classified as early or advanced stage based on MRA and posterior cerebral artery (PCA) involvement. Regional cerebral blood flow (rCBF) was measured with N-isopropyl-p-[123I]-iodoamphetamine SPECT. Furthermore, cognitive performance was examined using the Wechsler Adult Intelligence Scale, Third Edition and the Trail Making Test (TMT). Both voxel- and region of interest-based analyses were performed for groupwise comparisons, as well as correlation analysis, using parameters such as cognitive test scores; gray matter volume; fractional anisotropy (FA) of association fiber tracts, including the inferior frontooccipital fasciculus (IFOF) and superior longitudinal fasciculus (SLF); PCA involvement; and rCBF. RESULTS: Compared to the early stages, advanced stages of arterial occlusion in the left hemisphere were associated with a lower Performance IQ (p = 0.031), decreased anterior cingulate volumes (p = 0.0001, uncorrected), and lower FA in the IFOF, cingulum, and forceps major (all p < 0.01, all uncorrected). There was no significant difference in rCBF between the early and the advanced stage. In patients with an advanced stage, PCA involvement was correlated with a significantly lower Full Scale IQ (p = 0.036), cingulate volume (p < 0.01, uncorrected), and FA of the left SLF (p = 0.0002, uncorrected) compared to those with an intact PCA. The rCBF was positively correlated with FA of the SLF, IFOF, and forceps major (r > 0.34, p < 0.05). Global gray matter volumes were moderately correlated with TMT part A (r = 0.40, p = 0.003). FA values in the left SLF were moderately associated with processing speed (r = 0.40, p = 0.002). CONCLUSIONS: Although hemodynamic compensation may mask cerebral ischemia in advanced stages of adult moyamoya disease, the disease progression is detrimental to gray and white matter microstructure as well as cognition. In particular, additional PCA involvement in advanced disease stages may impair key neural substrates such as the cingulum and SLF. Thus, combined structural MRI and DTI are potentially useful for tracking the neural integrity of key neural substrates associated with cognitive function and detecting subtle anatomical changes associated with persistent ischemia, as well as disease progression.
  • 澤村 大輔, タ・キンキン
    作業療法ジャーナル (株)三輪書店 54 (3) 244 - 251 0915-1354 2020/03 
    ＜文献概要＞はじめに 近年では,脳画像技術や解析技術の目覚ましい発展により,非侵襲的に高い空間解像度で脳の構造,機能が可視化できるようになってきている.特に神経回路解析には各学問領域から注目が集まっている.神経回路解析は従来の技術で病態解明が困難とされていた種々の脳疾患の診断,脳腫瘍除去術の術前評価,予後予測についても有用であり,臨床応用されるようになってきている.また,アルツハイマー型認知症(Alzheimer's disease:AD)等の神経変性疾患における早期診断のバイオマーカーとしての役割も期待されている.MRIを用いた神経回路解析のイメージング法としては,解剖学的結合を評価する拡散MRI,機能的結合を評価する安静時機能MRI(resting state functional MRI:rsfMRI)がある.これらのイメージング法は従来の病巣解析とは異なり,神経ネットワークの生理状態や障害を評価するものである.拡散MRIは脳内における水分子の運動を捉えることにより大脳白質を中心とした脳の微細構造の情報を把握することができ,大脳皮質領域間の解剖学的結合を評価することができるイメージング法である.一方で,rsfMRIは,解剖学的な連結構造が仮定されない場合を含む離れた領域間の神経活動パターンの情報を捉え,その類似性より機能的結合を評価することができるイメージング法である.これらのイメージング法はリハ効果検討における神経可塑性の結果指標として,また予後予測の一助として利用されるようになってきている.ここではこの2つの代表的な脳イメージング法の基本原理を簡略に概説し,画像情報の解釈およびリハ関連領域の先行研究について紹介する.また,リハ領域における臨床応用が期待される近赤外線分光法(near-infrared spectroscopy:NIRS)についても触れたうえで,これらのイメージング法を作業療法に活かす視点を述べる.
  • 高倉祐樹, 澤村大輔, タキンキン, 大槻美佳
    CLINICAL REHABILITATION 医歯薬出版(株) 28 (12) 1132 - 1139 0918-5259 2019/11 [Refereed][Not invited]
  • Ken Kazumata, Khin Khin Tha, Kikutaro Tokairin, Masaki Ito, Haruto Uchino, Masahito Kawabori, Taku Sugiyama
    Neurosurgery 85 (5) E943-E952 - E952 0148-396X 2019/11/01 [Refereed][Not invited]
     
    BACKGROUND: The effect of the combined direct/indirect revascularization surgery in Moyamoya disease has not been evaluated sufficiently with regard to cognitive function, brain microstructure, and connectivity. OBJECTIVE: To investigate structural and functional changes following revascularization surgery in patients with moyamoya disease (MMD) through a combined analysis of brain morphology, microstructure, connectivity, and neurobehavioral data. METHODS: Neurobehavioral and neuroimaging examinations were performed in 25 adults with MMD prior to and >12 mo after revascularization surgery. Cognitive function was investigated using the Wechsler Adult Intelligence Scale-III, Trail-Making Test, Wisconsin Card Sorting Test, Continuous Performance Test, Stroop test, and Wechsler Memory Scale. We assessed white matter integrity using diffusion tensor imaging, brain morphometry using magnetization-prepared rapid gradient-echo sequences, and brain connectivity using resting-state functional magnetic resonance imaging (MRI). RESULTS: Cognitive examinations revealed significant changes in the full-scale intelligence quotient (IQ), performance IQ (PIQ), perceptual organization (PO), processing speed, and Stroop test scores after surgery (P < .05). Enlargement of the lateral ventricle, volume reductions in the corpus callosum and subcortical nuclei, and cortical thinning in the prefrontal cortex were also observed (P < .05). Fractional anisotropy in the white matter tracts, including the superior longitudinal fasciculus, increased 2 to 4 yr after surgery, relative to that observed in the presurgical state (P < .05). Resting-state brain connectivity was increased predominantly in the fronto-cerebellar circuit and was positively correlated with improvements in PIQ and PO (P < .05). CONCLUSION: Revascularization surgery may improve processing speed and attention in adult patients with MMD. Further, multimodal MRI may be useful for detecting subtle postsurgical brain structural changes, reorganization of white matter tracts, and brain connectivity alterations.
  • N Abe, M Kato, Y Fujieda, H Narita, K K Tha, T Atsumi
    Scandinavian journal of rheumatology 48 (6) 519 - 521 0300-9742 2019/11 [Refereed][Not invited]
  • Noriyuki Fujima, Akihiro Homma, Taisuke Harada, Yukie Shimizu, Khin Khin Tha, Satoshi Kano, Takatsugu Mizumachi, Ruijiang Li, Kohsuke Kudo, Hiroki Shirato
    Cancer imaging : the official publication of the International Cancer Imaging Society 19 (1) 5 - 5 1740-5025 2019/02/04 [Refereed][Not invited]
     
    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.
  • 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 (公社)日本医学放射線学会 37 (Suppl.) 4 - 4 1867-1071 2019/02
  • 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 (公社)日本医学放射線学会 37 (Suppl.) 10 - 10 1867-1071 2019/02
  • Haruna Watanabe, Ren Togo, Takahiro Ogawa, Miki Haseyama, Koichi Yasuda, Khin Khin Tha, Kohsuke Kudo, Hiroki Shirato
    INTERNATIONAL FORUM ON MEDICAL IMAGING IN ASIA 2019 11050 0277-786X 2019 [Refereed][Not invited]
     
    In this paper, we propose a method to classify metastatic bone tumors using treatment-planning computed tomography images. The proposed method utilizes pre-trained deep convolutional neural network (DCNN) models as feature extractors and enables the metastatic bone tumor classification by using the obtained features. Performance of several state-of-the-art DCNN-based features was compared and evaluated in our experiment.
  • 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 (一社)日本核医学会 55 (1) 40 - 40 0022-7854 2018/12
  • Minghui Tang, Kazuya Oshinomi, Kinya Ishizaka, Khin Khin Tha, Toru Yamamoto
    JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY 42 (4) 522 - 526 0363-8715 2018/07 [Refereed][Not invited]
     
    Objective The objective of this study was to show the effect of the number of sampling points (NS) and the maximum b value (b(max)) on fiber crossing detection in diffusion spectrum imaging (DSI) in clinical practice.Methods We performed 3-Tesla DSI in which we changed the NS (62-258) while keeping b(max) at 8000 s/mm(2) and in which we changed the b(max) (4000-8000 s/mm(2)) while keeping the NS at 129. The superior longitudinal fasciculus volume and the proportion of nerve voxels in which at least 2 (R-cr2) or 3 (R-cr3) nerve fiber bundles crossed were calculated.Results When b(max) was set to 8000 s/mm(2), mean R-cr2 and R-cr3 values and superior longitudinal fasciculus volumes significantly increased with higher NSs, but they did not significantly change when we varied b(max) with 129 NS.Conclusions Depiction sensitivity of nerve fiber crossing in DSI improves at higher NS and b(max) settings, but a b(max) insensitivity appears at an intermediate NS such as 129.
  • Jia Wu, Khin Khin Tha, Lei Xing, Ruijiang Li
    Journal of radiation research 59 (suppl_1) i25-i31 - I31 0449-3060 2018/03/01 [Refereed][Not invited]
     
    Imaging plays an important role in the diagnosis and staging of cancer, as well as in radiation treatment planning and evaluation of therapeutic response. Recently, there has been significant interest in extracting quantitative information from clinical standard-of-care images, i.e. radiomics, in order to provide a more comprehensive characterization of image phenotypes of the tumor. A number of studies have demonstrated that a deeper radiomic analysis can reveal novel image features that could provide useful diagnostic, prognostic or predictive information, improving upon currently used imaging metrics such as tumor size and volume. Furthermore, these imaging-derived phenotypes can be linked with genomic data, i.e. radiogenomics, in order to understand their biological underpinnings or further improve the prediction accuracy of clinical outcomes. In this article, we will provide an overview of radiomics and radiogenomics, including their rationale, technical and clinical aspects. We will also present some examples of the current results and some emerging paradigms in radiomics and radiogenomics for clinical oncology, with a focus on potential applications in radiotherapy. Finally, we will highlight the challenges in the field and suggest possible future directions in radiomics to maximize its potential impact on precision radiotherapy.
  • 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 (公社)日本医学放射線学会 36 (Suppl.) 3 - 3 1867-1071 2018/02
  • 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 (公社)日本医学放射線学会 36 (Suppl.) 13 - 13 1867-1071 2018/02
  • 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 (公社)日本医学放射線学会 36 (Suppl.) 16 - 16 1867-1071 2018/02
  • 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 2018/01 [Refereed]
     
    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.
  • Aono S, Ishizaka K, Tha KK, Takamori S, Aoike S, Fujiwara T
    Nihon Hoshasen Gijutsu Gakkai zasshi 74 (4) 335 - 343 0369-4305 2018 [Refereed][Not invited]
  • Naoki Hashimoto, Yoichi M Ito, Naohiro Okada, Hidenaga Yamamori, Yuka Yasuda, Michiko Fujimoto, Noriko Kudo, Ariyoshi Takemura, Shuraku Son, Hisashi Narita, Maeri Yamamoto, Khin Khin Tha, Asuka Katsuki, Kazutaka Ohi, Fumio Yamashita, Shinsuke Koike, Tsutomu Takahashi, Kiyotaka Nemoto, Masaki Fukunaga, Toshiaki Onitsuka, Yoshiyuki Watanabe, Hidenori Yamasue, Michio Suzuki, Kiyoto Kasai, Ichiro Kusumi, Ryota Hashimoto
    NeuroImage. Clinical 17 563 - 569 2018 [Refereed][Not invited]
     
    Background: The effect of duration of illness and antipsychotic medication on the volumes of subcortical structures in schizophrenia is inconsistent among previous reports. We implemented a large sample analysis utilizing clinical data from 11 institutions in a previous meta-analysis. Methods: Imaging and clinical data of 778 schizophrenia subjects were taken from a prospective meta-analysis conducted by the COCORO consortium in Japan. The effect of duration of illness and daily dose and type of antipsychotics were assessed using the linear mixed effect model where the volumes of subcortical structures computed by FreeSurfer were used as a dependent variable and age, sex, duration of illness, daily dose of antipsychotics and intracranial volume were used as independent variables, and the type of protocol was incorporated as a random effect for intercept. The statistical significance of fixed-effect of dependent variable was assessed. Results: Daily dose of antipsychotics was positively associated with left globus pallidus volume and negatively associated with right hippocampus. It was also positively associated with laterality index of globus pallidus. Duration of illness was positively associated with bilateral globus pallidus volumes. Type of antipsychotics did not have any effect on the subcortical volumes. Discussion: A large sample size, uniform data collection methodology and robust statistical analysis are strengths of the current study. This result suggests that we need special attention to discuss about relationship between subcortical regional brain volumes and pathophysiology of schizophrenia because regional brain volumes may be affected by antipsychotic medication.
  • Yi Cui, Shangjie Ren, Khin Khin Tha, Jia Wu, Hiroki Shirato, Ruijiang Li
    European radiology 27 (9) 3583 - 3592 2017/09 
    OBJECTIVE: To develop and validate a volume-based, quantitative imaging marker by integrating multi-parametric MR images for predicting glioblastoma survival, and to investigate its relationship and synergy with molecular characteristics. METHODS: We retrospectively analysed 108 patients with primary glioblastoma. The discovery cohort consisted of 62 patients from the cancer genome atlas (TCGA). Another 46 patients comprising 30 from TCGA and 16 internally were used for independent validation. Based on integrated analyses of T1-weighted contrast-enhanced (T1-c) and diffusion-weighted MR images, we identified an intratumoral subregion with both high T1-c and low ADC, and accordingly defined a high-risk volume (HRV). We evaluated its prognostic value and biological significance with genomic data. RESULTS: On both discovery and validation cohorts, HRV predicted overall survival (OS) (concordance index: 0.642 and 0.653, P < 0.001 and P = 0.038, respectively). HRV stratified patients within the proneural molecular subtype (log-rank P = 0.040, hazard ratio = 2.787). We observed different OS among patients depending on their MGMT methylation status and HRV (log-rank P = 0.011). Patients with unmethylated MGMT and high HRV had significantly shorter survival (median survival: 9.3 vs. 18.4 months, log-rank P = 0.002). CONCLUSION: Volume of the high-risk intratumoral subregion identified on multi-parametric MRI predicts glioblastoma survival, and may provide complementary value to genomic information. KEY POINTS: • High-risk volume (HRV) defined on multi-parametric MRI predicted GBM survival. • The proneural molecular subtype tended to harbour smaller HRV than other subtypes. • Patients with unmethylated MGMT and high HRV had significantly shorter survival. • HRV complements genomic information in predicting GBM survival.
  • Ken Kazumata, Khin Khin Tha, Haruto Uchino, Tohru Shiga, Hideo Shichinohe, Masaki Ito, Naoki Nakayama, Takeo Abumiya
    Journal of neurosurgery 127 (2) 260 - 269 0022-3085 2017/08 [Refereed][Not invited]
     
    OBJECTIVE After revascularization surgery, hyperperfusion and ischemia are associated with morbidity and mortality in adult moyamoya disease (MMD). However, structural changes within the brain following revascularization surgery, especially in the early postsurgical period, have not been thoroughly studied. Such knowledge may enable improved monitoring and clinical management of hyperperfusion and ischemia in MMD. Thus, the objective of this study was to investigate the topographic and temporal profiles of cerebral perfusion and related white matter microstructural changes following revascularization surgery in adult MMD. METHODS The authors analyzed 20 consecutive surgeries performed in 17 adults. Diffusion imaging in parallel with serial measurements of regional cerebral blood flow (rCBF) using SPECT was performed. Both voxel-based and region-of-interest analyses were performed, comparing neuroimaging parameters of postoperative hemispheres with those of preoperative hemispheres at 4 different time points within 2 weeks after surgery. RESULTS Voxel-based analysis showed a distinct topographic pattern of cerebral perfusion, characterized by increased rCBF in the basal ganglia for the first several days and gradually increased rCBF in the lateral prefrontal cortex over 1 week (p < 0.001). Decreased rCBF was also observed in the lateral prefrontal cortex, occipital lobe, and cerebellum contralateral to the surgical hemisphere (p < 0.001). Reduced fractional anisotropy (FA) and axial diffusivity (AD), as well as increased radial diffusivity (RD), were demonstrated in both the anterior and posterior limbs of the internal capsule (p < 0.001). Diffusion parameters demonstrated the greatest changes in both FA and RD on Days 1-2 and in AD on Days 3-6; FA, RD, and AD recovered to preoperative levels on Day 14. Patients with transient neurological deteriorations (TNDs), as compared with those without, demonstrated greater increases in rCBF in both the lateral prefrontal cortex and striatum as well as smaller FAs in the posterior limb of the internal capsule (p < 0.05). CONCLUSIONS The excessively increased rCBF and the recovery process were heterogeneous across brain regions, demonstrating a distinct topographic pattern during the initial 2 weeks following revascularization surgery in MMD. Temporary impairments in the deep white matter tract and immediate postoperative ischemia were also identified. The study results characterized postoperative brain perfusion as well as the impact of revascularization surgery on the brain microstructure. Notably, rCBF and white matter changes correlated to TNDs, suggesting that these changes represent potential neuroimaging markers for tracking tissue structural changes associated with hyperperfusion during the acute postoperative period following revascularization surgery for MMD.
  • Noriyuki Fujima, Tomohiro Sakashita, Akihiro Homma, Taisuke Harada, Yukie Shimizu, Khin Khin Tha, Kohsuke Kudo, Hiroki Shirato
    Oncotarget 8 (20) 33631 - 33643 2017/05/16 
    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 D2 and slow diffusion coefficient D3 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.
  • 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 0938-7994 2017/03 [Refereed][Not invited]
     
    OBJECTIVES: 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. METHODS: 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 Dk) 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. RESULTS: 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. CONCLUSIONS: IVIM and DKI parameters, especially the D-value's histogram 25th percentile, are useful for predicting local control. KEY POINTS: • 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.
  • 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 2017/02 
    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 (f2) and the volume of the extracellular extravascular space per unit volume of tissue (ve) 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.
  • Ken Kazumata, Khin Khin Tha, Haruto Uchino, Masaki Ito, Naoki Nakayama, Takeo Abumiya
    PloS one 12 (8) e0182759  1932-6203 2017 [Refereed][Not invited]
     
    Detection of subtle ischemic injuries in moyamoya disease may enable optimization of timing of revascularization surgery, and could potentially improve functional outcomes. Resting-state functional magnetic resonance imaging (rs-fMRI) is widely used to study functional organization of the brain, but it remains unclear whether rs-fMRI could elucidate distinct characteristics in moyamoya disease. Here, we aimed to determine changes in a conventional rs-fMRI measure and analyze any associations with clinical symptoms and cerebral hemodynamics. Thirty-one adults with moyamoya disease and 25 adult controls underwent rs-fMRI, in which we measured brain connectivity via temporal correlations of low-frequency BOLD signals. We identified the extent of between-group differences with multivoxel pattern analysis. Seed-based analysis was performed to determine associations with vascular lesions, symptoms, and regional cerebral blood flow (rCBF). There was significantly altered connectivity in the precentral gyrus, operculo-insular region, precuneus, cingulate cortex, and middle frontal gyrus in moyamoya disease. There was reduced connectivity in the left insula, left precuneus, right precentral, and right middle frontal regions, which form part of the salience, default mode, motor, and central executive networks, respectively. Patients with ischemic motor-related symptoms showed significantly decreased connectivity in precentral homotopic regions compared with those without, while there were no differences in vascular lesions or rCBF. Connectivity between the right occipital and left hippocampus was significantly associated with cognitive performance and posterior cerebral artery involvement. Our results demonstrate distinct alterations in the temporal correlations of low-frequency BOLD signals, predominantly in resting-state networks in moyamoya disease. Additionally, rs-fMRI measures were associated with ischemic motor-related symptoms and cognitive performance in the patients. Thus, rs-fMRI may offer a useful non-invasive method of acquiring additional information beyond cerebral perfusion as part of clinical investigations in patients with moyamoya disease.
  • 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 (一社)日本神経学会 56 (Suppl.) S62 - S62 0009-918X 2016/12
  • Hisashi Narita, Khin K Tha, Naoki Hashimoto, Hiroyuki Hamaguchi, Shin Nakagawa, Hiroki Shirato, Ichiro Kusumi
    Progress in neuro-psychopharmacology & biological psychiatry 71 169 - 75 0278-5846 2016/11/03 [Refereed][Not invited]
     
    INTRODUCTION: Diffusion kurtosis imaging can provide a better understanding of microstructural white matter (WM) changes where crossing fibers exist, compared with conventional diffusion tensor imaging. Here, we aimed to examine the differences of mean kurtosis (MK) and fractional anisotropy (FA) values between patients with schizophrenia and control subjects using voxel-based analysis (VBA). Additionally, we examined the correlation between these values and severity of clinical symptoms in patients with schizophrenia. METHODS: MK and FA values were acquired with a 3.0T scanner from 31 patients with schizophrenia and 31 age-, handedness-, and sex-matched healthy controls. VBA was used to compare the MK and FA maps of the patients with schizophrenia and healthy controls. We also performed a correlation analysis between the MK and FA values of the regions with significant differences and the positive and negative syndrome scale scores in patients with schizophrenia. RESULTS: Compared to FA values, voxels with MK decrease were more widespread across bilateral cerebral the WM of patients with schizophrenia. The MK values of left superior longitudinal fasciculus were significantly negatively correlated with the severity of positive symptoms (r=-0.451, P=0.011). There was no significant correlation between MK and FA values and other clinical variables. CONCLUSION: The diffusion kurtosis indices are suitable for evaluating altered WM structures in the human brain as they may detect white matter alterations of crossing fibers alterations of WM in schizophrenia and assess the clinical state of patients.
  • K Kazumata, K K Tha, H Narita, Y M Ito, H Shichinohe, M Ito, H Uchino, T Abumiya
    AJNR. American journal of neuroradiology 37 (8) 1432 - 9 2016/08 [Refereed][Not invited]
     
    BACKGROUND AND PURPOSE: Detecting microstructural changes due to chronic ischemia potentially enables early identification of patients at risk of cognitive impairment. In this study, diffusional kurtosis imaging and diffusion tensor imaging were used to investigate whether the former provides additional information regarding microstructural changes in the gray and white matter of adult patients with Moyamoya disease. MATERIALS AND METHODS: MR imaging (diffusional kurtosis imaging and DTI) was performed in 23 adult patients with Moyamoya disease and 23 age-matched controls. Three parameters were extracted from diffusional kurtosis imaging (mean kurtosis, axial kurtosis, and radial kurtosis), and 4, from DTI (fractional anisotropy, radial diffusivity, mean diffusivity, and axial diffusivity). Voxelwise analysis for these parameters was performed in the normal-appearing brain parenchyma. The association of these parameters with neuropsychological performance was also evaluated. RESULTS: Voxelwise analysis revealed the greatest differences in fractional anisotropy, followed, in order, by radial diffusivity, mean diffusivity, and mean kurtosis. In patients, diffusional kurtosis imaging parameters were decreased in the dorsal deep white matter such as the corona radiata and superior longitudinal fasciculus (P < .01), including areas without DTI abnormality. Superior longitudinal fasciculus fiber-crossing areas showed weak correlations between diffusional kurtosis imaging and DTI parameters compared with tissues with a single-fiber direction (eg, the corpus callosum). Diffusional kurtosis imaging parameters were associated with general intelligence and frontal lobe performance. CONCLUSIONS: Although DTI revealed extensive white matter changes, diffusional kurtosis imaging additionally demonstrated microstructural changes in ischemia-prone deep white matter with abundant fiber crossings. Thus, diffusional kurtosis imaging may be a useful adjunct for detecting subtle chronic ischemic injuries.
  • Hiroyuki Hamaguchi, Khin Khin Tha, Hiroyuki Sugimori, Mitsuhiro Nakanishi, Shin Nakagawa, Taro Fujiwara, Hirokazu Yoshida, Sayaka Takamori, Hiroki Shirato
    The neuroradiology journal 29 (4) 254 - 9 1971-4009 2016/08 [Refereed][Not invited]
     
    The effect of respiratory gating on the major diffusion-imaging metrics and that of cardiac gating on mean kurtosis (MK) are not known. For evaluation of whether the major diffusion-imaging metrics-MK, fractional anisotropy (FA), and mean diffusivity (MD) of the brain-varied between gated and non-gated acquisitions, respiratory-gated, cardiac-gated, and non-gated diffusion-imaging of the brain were performed in 10 healthy volunteers. MK, FA, and MD maps were constructed for all acquisitions, and the histograms were constructed. The normalized peak height and location of the histograms were compared among the acquisitions by use of Friedman and post hoc Wilcoxon tests. The effect of the repetition time (TR) on the diffusion-imaging metrics was also tested, and we corrected for its variation among acquisitions, if necessary. The results showed a shift in the peak location of the MK and MD histograms to the right with an increase in TR (p ≤ 0.01). The corrected peak location of the MK histograms, the normalized peak height of the FA histograms, the normalized peak height and the corrected peak location of the MD histograms varied significantly between the gated and non-gated acquisitions (p < 0.05). These results imply an influence of respiration and cardiac pulsation on the major diffusion-imaging metrics. The gating conditions must be kept identical if reproducible results are to be achieved.
  • Ken Kazumata, Khin Khin Tha, Hisashi Narita, Hideo Shichinohe, Masaki Ito, Haruto Uchino, Takeo Abumiya
    World neurosurgery 89 654 - 665 1878-8750 2016/05 [Refereed][Not invited]
     
    Chronic ischemia in adult moyamoya disease (MMD) reduces the integrity of normal-appearing white matter (WM). We investigated whether covert WM impairment alters large-scale brain networks and specific neural circuits associated with neurocognitive dysfunction in MMD. Forty-six participants (control, n = 23; MMD, n = 23) were examined using diffusion tensor imaging and streamline tractography. Structural connectivity among 90 cortical and subcortical brain regions was evaluated using the mean fractional anisotropy along the fiber tracts. Graph theoretical analysis was used to measure network parameters and inter-regional connectivity. Global network parameters were reduced in patients with MMD, including cluster coefficient (controls vs. MMD: 3.62 ± 0.24 vs. 3.26 ± 0.36; P < 0.0001), characteristic path length (controls vs. MMD: 1.20 ± 0.02 vs. 1.17 ± 0.01; P < 0.001), and small-world property (controls vs. MMD: 3.07 ± 0.18 vs. 2.83 ± 0.27; P < 0.001). Reduced pairwise connectivity was found in prefrontal neural circuits within the middle/inferior frontal gyrus; supplementary motor area; and insular, inferior temporal, and dorsal cingulate cortices. Covert WM microstructural changes in patients with MMD alter large-scale brain networks, as well as lateral prefrontal neural circuits. Evaluation of structural connectivity may be useful to assess the severity of chronic ischemic injury from a network perspective.
  • Rie Mimura, Fumi Kato, Khin Khin Tha, Kohsuke Kudo, Yosuke Konno, Noriko Oyama-Manabe, Tatsuya Kato, Hidemichi Watari, Noriaki Sakuragi, Hiroki Shirato
    Japanese journal of radiology 34 (3) 229 - 37 1867-1071 2016/03 [Refereed][Not invited]
     
    PURPOSE: This study aimed to evaluate whether histogram analysis of the apparent diffusion coefficient (ADC) of a solid tumor component could distinguish borderline ovarian tumors from ovarian carcinoma. MATERIALS AND METHODS: Sixteen pathologically proven borderline tumors and 21 carcinomas were retrospectively examined. Magnetic resonance (1.5-T) image data sets were coregistered, and the solid components of each tumor were semiautomatically segmented. ADC histograms of the solid components were extracted; modes, minimums, means, and 10th, 25th, 50th, 75th, and 90th percentiles of the histograms were compared between the two tumor types, and receiver-operating characteristic (ROC) analysis was performed. RESULTS: The mode, minimum, mean, 10th, 25th, 50th, and 75th percentile ADC values of solid components of borderline tumors were significantly larger than those of carcinomas. Among these, the 10th percentile values had the lowest p value (p = 0.0003). At ROC analysis, the area under the curve (AUC) in the 10th percentile was the greatest (0.854), and the best cutoff value in the 10th percentile provided the highest specificity (93.8 %). CONCLUSIONS: ADC histograms of solid tumor components facilitated the distinction between borderline ovarian tumors and carcinoma. The 10th percentile ADC values had the best diagnostic performance.
  • 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 2016/02 
    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.
  • Yi Cui, Khin Khin Tha, Shunsuke Terasaka, Shigeru Yamaguchi, Jeff Wang, Kohsuke Kudo, Lei Xing, Hiroki Shirato, Ruijiang Li
    Radiology 278 (2) 546 - 53 0033-8419 2016/02 [Refereed][Not invited]
     
    PURPOSE: To develop and independently validate prognostic imaging biomarkers for predicting survival in patients with glioblastoma on the basis of multiregion quantitative image analysis. MATERIALS AND METHODS: This retrospective study was approved by the local institutional review board, and informed consent was waived. A total of 79 patients from two independent cohorts were included. The discovery and validation cohorts consisted of 46 and 33 patients with glioblastoma from the Cancer Imaging Archive (TCIA) and the local institution, respectively. Preoperative T1-weighted contrast material-enhanced and T2-weighted fluid-attenuation inversion recovery magnetic resonance (MR) images were analyzed. For each patient, we semiautomatically delineated the tumor and performed automated intratumor segmentation, dividing the tumor into spatially distinct subregions that demonstrate coherent intensity patterns across multiparametric MR imaging. Within each subregion and for the entire tumor, we extracted quantitative imaging features, including those that fully capture the differential contrast of multimodality MR imaging. A multivariate sparse Cox regression model was trained by using TCIA data and tested on the validation cohort. RESULTS: The optimal prognostic model identified five imaging biomarkers that quantified tumor surface area and intensity distributions of the tumor and its subregions. In the validation cohort, our prognostic model achieved a concordance index of 0.67 and significant stratification of overall survival by using the log-rank test (P = .018), which outperformed conventional prognostic factors, such as age (concordance index, 0.57; P = .389) and tumor volume (concordance index, 0.59; P = .409). CONCLUSION: The multiregion analysis presented here establishes a general strategy to effectively characterize intratumor heterogeneity manifested at multimodality imaging and has the potential to reveal useful prognostic imaging biomarkers in glioblastoma.
  • 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 - 93 0720-048X 2015/11 [Refereed][Not invited]
     
    OBJECTIVES: To investigate the diagnostic value of tumor blood flow (TBF) obtained with pseudo-continuous 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.
  • 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 1053-1807 2015/04 [Refereed][Not invited]
     
    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.
  • 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 (公社)日本医学放射線学会 33 (Suppl.) 1 - 1 1867-1071 2015/02
  • Ken Kazumata, Khin Khin Tha, Hisashi Narita, Ichiro Kusumi, Hideo Shichinohe, Masaki Ito, Naoki Nakayama, Kiyohiro Houkin
    Stroke 46 (2) 354 - 60 0039-2499 2015/02 [Refereed][Not invited]
     
    BACKGROUND AND PURPOSE: The mechanisms underlying frontal lobe dysfunction in moyamoya disease (MMD) are unknown. We aimed to determine whether chronic ischemia induces subtle microstructural brain changes in adult MMD and evaluated the association of changes with neuropsychological performance. METHODS: MRI, including 3-dimensional T1-weighted imaging and diffusion tensor imaging, was performed in 23 adult patients with MMD and 23 age-matched controls and gray matter density and major diffusion tensor imaging indices were compared between them; any alterations in the patients were tested for associations with age, ischemic symptoms, hemodynamic compromise, and neuropsychological performance. RESULTS: Decrease in gray matter density, associated with hemodynamic compromise (P<0.05), was observed in the posterior cingulate cortex of patients with MMD. Widespread reduction in fractional anisotropy and increases in radial diffusivity and mean diffusivity in some areas were also observed in bilateral cerebral white matter. The fractional anisotropy (r=0.54; P<0.0001) and radial diffusivity (r=-0.41; P<0.01) of white matter significantly associated with gray matter density of the cingulate cortex. The mean fractional anisotropy of the white matter tracts of the lateral prefrontal, cingulate, and inferior parietal regions were significantly associated with processing speed, executive function/attention, and working memory. CONCLUSIONS: In adult MMD, there were more white matter abnormalities than gray matter changes. Disruption of white matter may play a pivotal role in the development of cognitive dysfunction.
  • Jeff Wang, Fumi Kato, Noriko Oyama-Manabe, Ruijiang Li, Yi Cui, Khin Khin Tha, Hiroko Yamashita, Kohsuke Kudo, Hiroki Shirato
    PloS one 10 (11) e0143308  1932-6203 2015 [Refereed][Not invited]
     
    OBJECTIVES: To determine the added discriminative value of detailed quantitative characterization of background parenchymal enhancement in addition to the tumor itself on dynamic contrast-enhanced (DCE) MRI at 3.0 Tesla in identifying "triple-negative" breast cancers. MATERIALS AND METHODS: In this Institutional Review Board-approved retrospective study, DCE-MRI of 84 women presenting 88 invasive carcinomas were evaluated by a radiologist and analyzed using quantitative computer-aided techniques. Each tumor and its surrounding parenchyma were segmented semi-automatically in 3-D. A total of 85 imaging features were extracted from the two regions, including morphologic, densitometric, and statistical texture measures of enhancement. A small subset of optimal features was selected using an efficient sequential forward floating search algorithm. To distinguish triple-negative cancers from other subtypes, we built predictive models based on support vector machines. Their classification performance was assessed with the area under receiver operating characteristic curve (AUC) using cross-validation. RESULTS: Imaging features based on the tumor region achieved an AUC of 0.782 in differentiating triple-negative cancers from others, in line with the current state of the art. When background parenchymal enhancement features were included, the AUC increased significantly to 0.878 (p<0.01). Similar improvements were seen in nearly all subtype classification tasks undertaken. Notably, amongst the most discriminating features for predicting triple-negative cancers were textures of background parenchymal enhancement. CONCLUSIONS: Considering the tumor as well as its surrounding parenchyma on DCE-MRI for radiomic image phenotyping provides useful information for identifying triple-negative breast cancers. Heterogeneity of background parenchymal enhancement, characterized by quantitative texture features on DCE-MRI, adds value to such differentiation models as they are strongly associated with the triple-negative subtype. Prospective validation studies are warranted to confirm these findings and determine potential implications.
  • Noriyuki Fujima, Daisuke Yoshida, Tomohiro Sakashita, Akihiro Homma, Akiko Tsukahara, Khin Khin Tha, Kohsuke Kudo, Hiroki Shirato
    Magnetic resonance imaging 32 (10) 1206 - 13 0730-725X 2014/12 [Refereed][Not invited]
     
    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 3T 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∙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∙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 f in 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∙D* and TBF were also similarly analyzed. RESULTS: In all combinations of f and TBV, f∙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∙D* and TBF, a good correlation was observed only with f∙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.
  • Shunsuke Onodera, Hidefumi Aoyama, Khin Khin Tha, Naoki Hashimoto, Atsuhito Toyomaki, Satoshi Terae, Hiroki Shirato
    Journal of neuro-oncology 120 (2) 311 - 9 0167-594X 2014/11 [Refereed][Not invited]
     
    To investigate whether the neurocognitive function at 4 months could be a relevant primary endpoint in clinical trials dealing with brain metastases, we created a Japanese neurocognitive battery and examined the changes in patients' neurocognitive function for 1 year after their brain radiotherapy. In this prospective pilot study, we enrolled 27 patients (20 patients who received whole-brain radiation therapy [WBRT] and seven who received stereotactic irradiation [STI] alone) between March 2009 and December 2010. The follow-up neurocognitive data at 4, 8 and 12 months were available in 22 (17 WBRT, 5 STI), 19 patients (14 WBRT, 5 STI) and 13 patients (9 WBRT, 4 STI), respectively. Among the patients who received WBRT, significant deterioration in delayed memory compared to the baseline (p = 0.04) was observed at 4 months, and at 8 months, significant improvements were observed in immediate memory compared to the baseline (p = 0.008) and 4-months scores (p = 0.005). At 12 months, however, the immediate memory scores had returned to the baseline. Similar trends were observed in other functions (delayed memory, attention and executive functions). In these patients, the correlations between 4-months scores of neurocognitive functions and 12-months scores were significant in immediate memory (γ = 0.68, p = 0.004), delayed memory (γ = 0.738, p = 0.023) and attention (γ = 0.817, p = 0.007). Among the patients who received STI, no significant changes were observed in any functions. These results suggest that 4-months changes in neurocognitive functions were transient but could also be a premonitory index for predicting the neurocognitive function 1 year or later after brain radiation therapy.
  • 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 : JMRI 40 (4) 920 - 8 1053-1807 2014/10 [Refereed][Not invited]
     
    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.
  • 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 1971-4009 2013/10 [Refereed][Not invited]
     
    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.
  • 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 0165-1781 2013/06/30 [Refereed][Not invited]
     
    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.
  • I. Yabe, K. K. Tha, H. Hamaguchi, K. Sakushima, T. Kano, S. Terae, H. Sasaki
    MOVEMENT DISORDERS 28 S235 - S235 0885-3185 2013/06 [Refereed][Not invited]
  • DTI撮像における撮像体位の影響
    濱口 裕行, 高森 清華, 谷川原 綾子, 水戸 寿々子, 杉森 博行, 石坂 欣也, Tha Khin Khin
    北海道放射線技術雑誌 (公社)日本放射線技術学会-北海道支部 (74) 26 - 27 0912-0327 2013/03
  • Small FOV Imagingにおける画質の基礎的検討
    濱口 裕行, 杉森 博行, キンキンタ, 高森 清華, 谷川原 綾子, 藤原 太郎, 吉田 博一
    日本放射線技術学会総会学術大会予稿集 (公社)日本放射線技術学会 69回 300 - 300 1884-7846 2013/02
  • Association of Renal Volume with the Degree of Aortic Contrast Enhancement in Abdominal CT
    Muto NS, Kamishima T, Sasaki T, Terae S, Tha KK, Shirato H, Bae KT
    Advances in Computed Tomography 2 55 - 62 2013 [Refereed][Not invited]
  • 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 0363-8715 2013/01 [Refereed][Not invited]
     
    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.
  • DTI撮像における撮像本位の影響
    濱口 裕行, 高森 清華, 谷川原 綾子, 杉森 博行, 石坂 欣也, 水戸 寿々子, Tha Khin Khin
    北海道放射線技術雑誌 (公社)日本放射線技術学会-北海道支部 (73) 105 - 105 0912-0327 2012/11
  • Daisuke Abo, Yu Hasegawa, Yusuke Sakuhara, Satoshi Terae, Tadashi Shimizu, Khin Khin Tha, Eiichi Tanaka, Satoshi Hirano, Satoshi Kondo, Hiroki Shirato
    Journal of hepato-biliary-pancreatic sciences 19 (4) 431 - 7 1868-6974 2012/07 [Refereed][Not invited]
     
    PURPOSE: To describe the feasibility of a dual microcatheter-dual interlocking detachable coil (DMDI) technique for preoperative embolization of the common hepatic artery (CHA) in preparation for distal pancreatectomy with en bloc celiac axis resection (DP-CAR) for locally advanced pancreatic body cancer. METHODS: From January 2007 to December 2009, 26 patients underwent embolization of the CHA by the DMDI technique. We compared the results with those of 37 patients in whom the CHA was embolized by conventional techniques from August 1998 to February 2007. RESULTS: With the DMDI technique, no coil migration or other embolization-related complications occurred. The success rate was 100%. The rate of embolization-related complications was significantly lower in the DMDI embolization group (0%) than in the conventional embolization group (24.3%) (P = 0.008). The frequency of improper positioning of the embolic material necessitating its removal during DP-CAR was significantly lower in the DMDI embolization group (10%) than in the conventional embolization group (37.5%) (P = 0.044). CONCLUSION: The DMDI technique allows the development of collateral pathways, reduces the surgeon's burden in ligating the distal CHA, and prevents coil migration. For these reasons, we believe that this technique is feasible for embolization of the CHA in preparation for DP-CAR for locally advanced pancreatic body cancer.
  • Khin K Tha, Satoshi Terae, Akiko Tsukahara, Hiroyuki Soma, Ryo Morita, Ichiro Yabe, Yoichi M Ito, Hidenao Sasaki, Hiroki Shirato
    BMC neurology 12 39 - 39 1471-2377 2012/06/18 [Refereed][Not invited]
     
    BACKGROUND: Hyperintense putaminal rim (HPR) is an important magnetic resonance imaging (MRI) sign for multiple system atrophy (MSA). Recent studies have suggested that it can also be observed in normal subjects at 3 T. Whether it can be observed in normal subjects at 1.5 T is not known. This study aimed to determine whether HPR could be observed in normal subjects at 1.5 T; and if so, to establish its prevalence, the MRI characteristics, and the features which distinguish from HPR in MSA patients. METHODS: Axial T2-weighted images of 130 normal subjects were evaluated for the prevalence of HPR, its age and gender distribution, laterality, maximum dimension, association with hypointensity of nearby putamen, and presence of discontinuity. To distinguish from that observed in MSA, axial T2-weighted images of 6 MSA patients with predominant parkinsonism (MSA-P) and 15 MSA patients with predominant cerebellar symptoms (MSA-C) were also evaluated. The characteristics of HPR were compared between these patients and age-matched normal subjects. The mean diffusivity (MD) values of putamen were also compared. Fisher's exact test, t-test, and one way analysis of variance were used to determine significance at corrected p < 0.05. RESULTS: HPR was observed in 38.5% of normal subjects. Age and gender predilection and laterality were not observed. In most cases, it occupied the full length or anterior half of the lateral margin of putamen, and was continuous throughout its length. Maximum transverse dimension was 2 mm. There was no association with hypointensity of nearby putamen. However, in MSA-P, HPR was located predominantly at the posterolateral aspect of putamen, and associated with putaminal atrophy. Discontinuity of HPR was more frequently observed in MSA-P. On visual analysis, the characteristics of HPR were similar between MSA-C patients and normal subjects. Patients with MSA of either type had significantly higher MD values of putamen than normal subjects. CONCLUSIONS: HPR can be observed in 38.5% of normal subjects at 1.5 T. Thin linear hyperintensity without discontinuity, occupying the full length or anterior half of the lateral margin of the putamen, is suggestive of "normal." In doubtful cases, measurement of the MD values of nearby putamen may be valuable.
  • Yusuke Sakuhara, Daisuke Abo, Yu Hasegawa, Tadashi Shimizu, Toshiya Kamiyama, Satoshi Hirano, Daisuke Fukumori, Takeshi Kawamura, Yoichi M Ito, Khin Khin Tha, Hiroki Shirato, Satoshi Terae
    AJR. American journal of roentgenology 198 (4) 914 - 22 0361-803X 2012/04 [Refereed][Not invited]
     
    OBJECTIVE: The purpose of this article is to evaluate the feasibility and efficacy of preoperative percutaneous transhepatic portal vein embolization with ethanol injection. MATERIALS AND METHODS: We retrospectively evaluated 143 patients who underwent percutaneous transhepatic portal vein embolization. Hypertrophy of the future liver remnant was assessed by comparing the volumetric data obtained from CT image data before and after percutaneous transhepatic portal vein embolization. The evaluation of effectiveness was based on changes in the absolute volume of the future liver remnant and the ratio of the future liver remnant to the total estimated liver volume. RESULTS: Ten of 143 patients (7.0%) underwent additional embolization because of recanalization and insufficient hypertrophy of the future liver remnant. The mean increase in the ratio of the future liver remnant was 33.6% (p < 0.0001), and the mean ratio of future liver remnant to total estimated liver volume increased from 34.9% to 45.7% (p < 0.0001). Although most of the patients complained of pain after ethanol injection, they were gradually relieved of pain in a few minutes by conservative treatment. Fever (38-39°C) was reported after 47 of 151 (31.1%) percutaneous transhepatic portal vein embolization sessions and was resolved within a few days. Transient elevation of the liver transaminases was observed after the procedures and resolved within about a week. Major complications occurred in nine of 151 (6%) percutaneous transhepatic portal vein embolization sessions, but no patients developed hepatic insufficiency or severe complications precluding successful resection. One hundred twenty patients underwent hepatic resection, and two patients developed hepatic failure after surgery. CONCLUSION: Preoperative percutaneous transhepatic portal vein embolization with ethanol is a feasible and effective procedure to obtain hypertrophy of the future liver remnant for preventing hepatic failure after hepatectomy.
  • 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 (公社)日本医学放射線学会 30 (Suppl.I) 12 - 12 1867-1071 2012/02
  • Diffusion tensor imaging in major depression
    Nakagawa S, Tha KK, Koyama T
    躁うつ病の薬理・生化学的研究談話会編：気分紹介の薬理・生化学：うつ病の脳内メカニズム研究：進歩と挑戦 324 - 325 2012 [Not refereed][Not invited]
  • 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 0033-8419 2011/12 [Refereed][Not invited]
     
    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.
  • Noriko Oyama-Manabe, Naoki Ishimori, Hiroyuki Sugimori, Marc Van Cauteren, Kohsuke Kudo, Osamu Manabe, Tomoyuki Okuaki, Tamotsu Kamishima, Yoichi M Ito, Hiroyuki Tsutsui, Khin Khin Tha, Satoshi Terae, Hiroki Shirato
    European radiology 21 (11) 2362 - 8 0938-7994 2011/11 [Refereed][Not invited]
     
    OBJECTIVES: To investigate whether subendocardial and transmural myocardial infarction can be identified and differentiated using the peak circumferential and longitudinal strains measured by fast strain-encoded (SENC). METHODS: Nineteen patients with ischemic heart diseases underwent imaging with fast SENC and late gadolinium enhancement (LGE) MRI at 3 T. Fast SENC measurements were performed in three short-axis slices (basal, mid-ventricular and apical levels) and one long-axis view (four-chamber) to assess peak longitudinal and circumferential systolic strains. RESULTS: All patients showed myocardial infarction with an average of 7 positive LGE segments. A total of 304 segments for longitudinal strains (LS) and 114 segments for circumferential strains (CS) could be analysed. Positive LGE segments showed lower peak CS and LS compared with the no LGE segments (P < 0.0001 for both). Segments with subendocardial infarction showed reduced CS and LS compared with the no LGE segments (P < 0.0001 for both). There was a significant difference in CS between subendocardial and transmural infarct segments (P = 0.03), but no significant difference in LS between them (P = 0.64). CONCLUSIONS: Fast SENC can identify old myocardial infarction and differentiate subendocardial from transmural infarction.
  • Kentaro Kobayashi, Khin Khin Tha, Satoshi Terae, Yuki Iijima, Kenichi Katabami, Yosuke Minami, Shinji Uegaki, Satoshi Gando, Hiroki Shirato
    JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY 35 (4) 498 - 500 0363-8715 2011/07 [Refereed][Not invited]
     
    We report a case of heat stroke in which detection of brain injury was improved by high b-value diffusion-weighted imaging (DWI). High b-value DWI revealed moderate to marked hyperintensity at/around bilateral dentate nuclei and part of thalami. Apparent diffusion coefficient maps revealed apparent diffusion coefficient decrease of the dentate lesions. Routine DWI showed only mild hyperintensity of part of dentate lesions. High b-value DWI could be valuable for improved detection of heat stroke-induced brain injury.
  • 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 - 9 1053-8119 2011/01/01 [Refereed][Not invited]
     
    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.
  • Ichiro Yabe, Khin K Tha, Takashi Yokota, Kazunori Sato, Hiroyuki Soma, Asako Takei, Satoshi Terae, Koichi Okita, Hidenao Sasaki
    Movement disorders : official journal of the Movement Disorder Society 26 (1) 165 - 8 0885-3185 2011/01 [Refereed][Not invited]
     
    The aim of this study was to determine if muscle energy metabolism, as measured by (31)P-magnetic resonance spectroscopy (MRS), is a metabolic marker for the efficacy of treatment of Machado-Joseph disease (MJD). We obtained (31)P-MRS in the calf muscle of 8 male patients with MJD and 11 healthy men before, during, and after a 4 minute plantar flexion exercise in a supine position. The data showed that there was a significant difference between the groups in terms of the PCr/(Pi + PCr) ratio at rest (P = 0.03) and the maximum rate of mitochondrial ATP production (V(max)) (P < 0.01). In addition, V(max) was inversely correlated with the scale for the assessment and rating of ataxia score (r = -0.34, P = 0.04). The MJD group also showed a reduction in V(max) over the course of 2 years (P < 0.05). These data suggest that this noninvasive measurement of muscle energy metabolism may represent a surrogate marker for MJD.
  • Tha KK, Terae S, Ishizaka K, Okuaki T, Hirotani M, Fujima N, Tsukahara A, Shirato H
    日本磁気共鳴医学会雑誌 31 (1) 70 - 70 0914-9457 2011 [Not refereed][Invited]
  • 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 0033-8419 2010/05 [Refereed][Not invited]
     
    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.
  • 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 - 9 0033-8419 2010/03 [Refereed][Not invited]
     
    PURPOSE: To evaluate the efficacy of susceptibility-weighted (SW) magnetic resonance (MR) imaging for the assessment of the posttreatment 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.
  • 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 : JMRI 31 (1) 32 - 8 1053-1807 2010/01 [Refereed][Not invited]
     
    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.
  • 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 0363-8715 2010/01 [Refereed][Not invited]
     
    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.
  • S. Onodera, H. Aoyama, N. Hashimoto, A. Toyomaki, N. Nishikawa, K. K. Tha, K. Ogisu, S. Terae, H. Shirato
    INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 78 (3) S293 - S293 0360-3016 2010 [Refereed][Not invited]
  • K K Tha, S Terae, K Kudo, K Miyasaka
    The British journal of radiology 82 (979) 610 - 4 0007-1285 2009/07 [Refereed][Not invited]
     
    The fluid-attenuated inversion recovery imaging sequence is a widely used MRI sequence of the brain. It is an inversion recovery pulse sequence, designed to suppress signals from the cerebrospinal fluid. It is highly sensitive for detection of lesions adjacent to or within the cerebrospinal fluid, associated with T(2) prolongation or T(1) shortening. The term "hyperintense cerebrospinal fluid" is used to describe failed suppression or hyperintensity of cerebrospinal fluid on fluid-attenuated inversion recovery imaging of the brain. It is often encountered in many important pathological conditions, including subarachnoid haemorrhage, meningitis and leptomeningeal metastasis. However, certain non-pathological states in which there is no definite cerebrospinal fluid abnormality can also present with hyperintense cerebrospinal fluid. Correct interpretation of abnormalities is important to arrive at an appropriate diagnosis. This pictorial review provides fluid-attenuated inversion recovery images of hyperintense cerebrospinal fluid of the brain and describes distinguishing features, focusing on non-pathological conditions.
  • K K Tha, S Terae, K Kudo, K Miyasaka
    The British journal of radiology 82 (977) 426 - 34 0007-1285 2009/05 [Refereed][Not invited]
     
    The fluid-attenuated inversion recovery imaging sequence is a widely used MRI sequence of the brain. It is an inversion recovery pulse sequence, designed to suppress signals from the cerebrospinal fluid. It is highly sensitive in detection of lesions adjacent to or within the cerebrospinal fluid associated with T(2) prolongation or T(1) shortening. The term "hyperintense cerebrospinal fluid" is used to describe failed suppression, or hyperintensity, of cerebrospinal fluid on fluid-attenuated inversion recovery imaging of the brain. It is often encountered in many important pathological conditions, including subarachnoid haemorrhage, meningitis and leptomeningeal metastasis. However, certain non-pathological states in which there is no definite cerebrospinal fluid abnormality can also present with hyperintense cerebrospinal fluid. Correct interpretation of abnormalities is important to arrive at an appropriate diagnosis. This pictorial review provides fluid-attenuated inversion recovery images of hyperintense cerebrospinal fluid of the brain and describes distinguishing features. Part I features pathological conditions whereas Part II focuses on non-pathological conditions.
  • 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 (公社)日本医学放射線学会 27 (Suppl.) 4 - 4 1867-1071 2009/04
  • I. Yabe, K. K. Tha, S. Terae, K. Okita, H. Sasaki
    MOVEMENT DISORDERS 23 (1) S148 - S148 0885-3185 2008 [Refereed][Not invited]
  • Satoshi Terae, Daisuke Yoshida, Kohsuke Kudo, Khin Khin Tha, Masaharu Fujino, Kazuo Miyasaka
    Journal of magnetic resonance imaging : JMRI 25 (3) 479 - 87 1053-1807 2007/03 [Refereed][Not invited]
     
    PURPOSE: To assess whether the use of postcontrast fluid-attenuated inversion recovery (FLAIR) imaging in combination with pre- and postcontrast magnetization transfer (MT) T1-weighted imaging (T1WI) can increase diagnostic confidence in the evaluation of brain metastases. MATERIALS AND METHODS: Brain MR images from 41 patients with suspected brain metastases were reviewed. Two radiologists viewed pre- and postcontrast MT-T1W images for the presence of metastatic tumors and rated the possible enhanced lesions using a five-point confidence scale (session 1). The postcontrast FLAIR images were then viewed together with pre- and postcontrast MT-T1W images, and the presence of metastasis was rated again (session 2). RESULTS: A total of 240 possible enhanced lesions were detected in session 1. Judging by follow-up MR examinations, 196 were considered to be nonmetastatic findings and 44 were determined to be metastasis. In session 2 the confidence rating for nonmetastasis increased significantly in the subset of nonmetastatic findings (P < 0.001), and the confidence rating for metastasis increased significantly in the subset of metastases (P < 0.05). CONCLUSION: The addition of postcontrast FLAIR imaging to pre- and postcontrast MT-T1WI improves diagnostic confidence in evaluation of brain metastases.
  • Yuri Yoshida, Satoshi Terae, Kohsuke Kudo, Khin Khin Tha, Masahiro Imamura, Kazuo Miyasaka
    JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY 30 (6) 980 - 982 0363-8715 2006/11 [Refereed][Not invited]
     
    A case of brain stem capillary telangiectasia diagnosed by susceptibility-weighted imaging is reported. A small enhancing pontine lesion was found on postcontrast T1 -weighted MR images in a 56-year-old woman with human T-cell leukemia virus type I infection. Imaging diagnosis was difficult with conventional MR imaging because the lesion did not show characteristic signal loss on conventional gradient-echo images. SWI was useful for imaging diagnosis as it demonstrated marked signal loss of the lesion.
  • KK Tha, S Terae, K Kudo, T Yamamoto, S Hamada, A Ogata, H Sasaki, K Miyasaka
    JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY 30 (1) 126 - 130 0363-8715 2006/01 [Refereed][Not invited]
     
    The authors report a case of subacute sclerosing pariencephalitis in which the diagnosis was suggested by high b-value diffusion-weighted imaging (DWI) findings. The signal abnormalities were located asymmetrically at bilateral cerebral corticosubcortical regions. High b-value DWI showed these signal abnormalities as marked hyperintensity with decreased apparent diffusion coefficient values. The signal abnormalities were difficult to identify on other magnetic resonance imaging sequences, including routine DWI. High b-value DWI could be valuable for earlier detection of subacute sclerosing panencephalitis.
  • Emiko Kaito, Satoshi Terae, Ryoji Kobayashi, Kohsuke Kudo, Khin Khin Tha, Kazuo Miyasaka
    Pediatric radiology 35 (7) 722 - 7 0301-0449 2005/07 [Refereed][Not invited]
     
    We report on a child with B-cell lymphoma who developed hypertension and reversible posterior leukoencephalopathy syndrome (RPLS) after chemotherapy conducted during recovery from tumor lysis syndrome. After recovery from RPLS, the patient received further combination chemotherapy without recurrence of the neurological signs or symptoms suggestive of RPLS. Many etiological factors have been reported in the development of RPLS; however, little attention has been paid to tumor lysis syndrome as a contributory factor for RPLS. Tumor lysis syndrome can precipitate the development of RPLS in patients with hematological malignancies who are undergoing chemotherapy. Knowledge and awareness would help facilitate immediate management such as normalization of blood pressure and temporary cessation of chemotherapy, helping to avoid irreversible brain damage.
  • KK Tha, S Terae, T Yamamoto, K Kudo, C Takahashi, M Oka, S Uegaki, K Miyasaka
    AMERICAN JOURNAL OF NEURORADIOLOGY 26 (6) 1487 - 1497 0195-6108 2005/06 [Refereed][Not invited]
     
    BACKGROUND AND PURPOSE: Early and accurate detection of global cerebral anoxia is important for determination of prognosis and further management. We evaluated whether accuracy in early detection of global cerebral anoxia was improved by high-b-value diffusion-weighted imaging (DWI) with long echo time (TE).METHODS: Routine DWI (b = 1000 s/mm(2); TE = 139 ms), high-b-value DWI (b = 3000 s/mm(2); TE = 190 ms), T2-weighted imaging (T2WI), and fluid-attenuated inversion recovery (FLAIR) imaging were acquired in six patients who experienced cardiopulmonary arrest within 24 hours and six volunteers. Region of interest-based analysis was performed. Regions of interest of patients showing significant decrease in apparent diffusion coefficient (ADC)3 values than volunteers were considered abnormal. Three neuroradiologists independently assessed images of the patients for conspicuity of hyperintensity within regions of interest. Receiver operating characteristic (ROC) analysis was performed, and the area under the curve (Az) was compared among sequences and observers. Average contrast and contrast-to-noise ratios between abnormal regions of interest and regions of interest of normal surrounding parenchyma were calculated.RESULTS: For all observers, high-b-value DWIs achieved the largest Az, and FLAIR imaging the lowest Az. Az of routine DWI and T2WI were between these values. High-b-value DWI and FLAIR imaging showed no significant interobserver variation in Az, whereas routine DWI and T2WI did. High-b-value DWI also achieved the largest contrast and contrast-to-noise ratios.CONCLUSION. High-b-value DWI with long TE improved accuracy in early detection of global cerebral anoxia. Application of the sequence would facilitate early diagnosis.
  • Kohsuke Kudo, Satoshi Terae, Aki Ishii, Tokuhiko Omatsu, Takeshi Asano, Khin Khin Tha, Kazuo Miyasaka
    AJNR. American journal of neuroradiology 25 (4) 551 - 7 0195-6108 2004/04 [Refereed][Not invited]
     
    BACKGROUND AND PURPOSE: Blood flow of the internal jugular vein and intracranial venous sinuses is affected by respiratory state. The purpose of this study was to clarify the changes in flow velocity and direction and signal intensities of sigmoid sinuses on phase-contrast (PC) MR images obtained with regular breathing and with deep inspiratory breath holding. METHODS: One hundred seven subjects without venous sinus abnormality were studied. Coronal 2D PC MR venography and axial 2D PC images with peripheral pulse gating were acquired with a 1.5-T MR unit, during regular breathing and deep inspiratory breath holding. The signal intensity changes of bilateral sigmoid sinuses on MR venograms and the changes of flow velocity and direction on the axial 2D PC images were analyzed. RESULTS: Breath holding decreased signal intensities of the right and left sigmoid sinuses on MR venograms in 57 (53.3%) and 36 (33.6%) subjects, respectively. Increased signal intensity was observed in 12 (11.2%) and 33 (30.8%) subjects, respectively. In the flow analysis, retrograde flow was detected at the left sigmoid sinus in four subjects (3.7%) during regular breathing, which was normalized by breath holding. Flow velocities of the right and left sigmoid sinuses decreased during breath holding in 92 (86.0%) and 70 (65.4%) subjects, and increased in 15 (14.0%) and 37 (34.6%) subjects, respectively. CONCLUSION: The signal intensities of sigmoid sinuses were affected by breath holding in about 2/3 of the subjects. Breath-holding maneuver can be used to increase blood flow and signal intensities of dural venous sinuses on PC MR venograms.
  • M Oka, S Terae, R Kobayashi, Y Sawamura, K Kudoh, K K Tha, M Yoshida, M Kaneda, Y Suzuki, K Miyasaka
    Neuroradiology 45 (7) 493 - 7 0028-3940 2003/07 [Refereed][Not invited]
     
    We report two fatal cases of methotrexate (MTX)-induced disseminated necrotising leukoencephalopathy (DNL) in which MRI was repeated from the onset. Initial T2-weighted images showed multiple areas of high signal, mainly in deep cerebral white matter, which on follow-up, spread and coalesced to involve the entire white matter. Small irregular low-signal foci on T2-weighted images were seen within the high-signal lesions. Multiple areas of contrast enhancement corresponded to these low-signal foci. The condition of both patients deteriorated and they died. We compared their MRI findings with those of seven patients with mild MTX-related leukoencephalopathy, six of whom were asymptomatic; one had transient neurological symptoms. They showed no contrast enhancement, but rather mild-to-moderate diffuse high signal in deep white matter, which later disappeared. These findings suggest that multiple low-signal foci on T2-weighted images with contrast enhancement may be characteristic of DNL, and that contrast-enhanced imaging is useful to differentiate this condition from mild leukoencephalopathy.
  • K K Tha, S Terae, M Sugiura, T Nishioka, M Oka, K Kudoh, K Kaneko, K Miyasaka
    Acta neurologica Scandinavica 106 (6) 379 - 86 0001-6314 2002/12 [Refereed][Not invited]
     
    We report a case of 5-fluorouracil (5-FU)-induced leukoencephalopathy in which magnetic resonance imaging (MRI) of the brain, including diffusion-weighted imaging (DWI), was performed serially. The initial T2-weighted and FLAIR images showed diffuse mild hyperintensity in bilateral deep cerebral white matter and corpus callosum, which on T1WI appeared as non-enhanced faint hypointensity. Isotropic DWI disclosed the abnormality as well-conspicuous diffuse hyperintensity with decreased ADC. Serial studies revealed that majority of the abnormal signal intensity on these sequences resolved, and the decreased ADC values approached normal. Some hyperintensity remained in the deep cerebral white matter and the splenium, but no further significant ADC change after normalization was noted. Measurement of ADC along the three orthogonal directions showed the presence of directional dependence of diffusion throughout the length of study. These findings suggest that early stage of 5-FU-induced leukoencephalopathy is associated with reversible restricted diffusion and preservation of anisotropy. Diffusion-weighted imaging may be useful for the diagnosis.

MISC

Books etc

  • Khin Khin Tha (Joint workSpinal cord)
    Gakken 2022/12
  • Pathways to radiomics-aided clinical decision-making for precision medicine
    Niu T, Sun X, Yang P, Cao G, Tha KK, Shirato H, Horst K, Xing L (Joint work)
    2019/07
  • うつ病患者における脳拡散テンソル画像
    Nakagawa S, Tha KK, Koyama T. (Joint work)
    医薬ジャーナル社出版，大阪 2012

Presentations

Teaching Experience

  • Functional Imaging Techniques for Biomedical Science and EngineeringFunctional Imaging Techniques for Biomedical Science and Engineering Hokkaido University Graduate School of Biomedical Science and Engineering
  • Radiologic Anatomy for Biomedical Science and EngineeringRadiologic Anatomy for Biomedical Science and Engineering Hokkaido University Graduate School of Biomedical Science and Engineeing
  • Diagnostic Radiology for Biomedical Science and EngineeringDiagnostic Radiology for Biomedical Science and Engineering Graduate School of Biomedical Science and Engineering
  • Radiologic AnatomyRadiologic Anatomy Hokkaido University School of Medicine
  • A deep look into the brain with MRIA deep look into the brain with MRI Hokkaido Summer Institute
  • Applied physics to explore the anatomy and pathology of the brainApplied physics to explore the anatomy and pathology of the brain Hokkaido Summer Institute
  • Imaging analytics for in vivo assessment of tumor biology: radiomics and radiogenomicsImaging analytics for in vivo assessment of tumor biology: radiomics and radiogenomics Summer School for Molecular Biomedical Science and Engineering School 2020
  • MRI techniques for in vivo assessment of tumor environment: diffusion imaging and beyondMRI techniques for in vivo assessment of tumor environment: diffusion imaging and beyond Summer School for Molecular Biomedical Science and Engineering School 2020

Association Memberships

  • Japanese Society of Magnetic Resonance in Medicine   Japanese Society of Neuroradiology   Japanese Society of Radiology   European Society of Radiology   International Society for Magnetic Resonance in Medicine   Radiological Society of North America   

Works

  • FA database
    Tha KK, Terae S, Kudo K, Miyasaka K 2005/04 -2007/04
  • ATLAS https://atlas.cira-s.jp/Atlas/
    Codeveloped with PSP Co. Ltd

Research Projects

  • 日本学術振興会：科学研究費助成事業
    Date (from‐to) : 2024/04 -2027/03 
    Author : Tha KhinKhin, 須藤 英毅
  • 日本学術振興会：科学研究費助成事業
    Date (from‐to) : 2022/04 -2025/03 
    Author : 澤村 大輔, Tha KhinKhin, 境 信哉
     
    今年度は、北海道道大学病院リハビリテーション科、リハビリテーション部との連携体制を整え、脳損傷患者のリクルートを開始するための準備に取り組んできた。また、北大病院の協力のもと、パイロットスタディーとして、3例の脳損傷患者のデータを取得した。3例に対して1日1時間，週5回，4週間のcomputerized cognitive trainingを施行し、その前後でトレーニングと同じ認知機能（注意、ワーキングメモリ）および異なる認知機能を評価する神経心理学的検査（記憶、遂行機能、情報処理速度など）を実施した。 トレーニング内容としては、トレーニング課題の成績に応じて課題難易度が自動調整されるシステムを構築しており、当初懸念していた課題難易度の問題（対象者において課題難易度が高く、トレーニング開始時から終了時まで難易度が変化しない）は参加者3例に共通して生じなかった。結果として、トレーニング終了後においてトレーニング課題の成績の向上（課題特異的効果）だけでなく、同じ注意、ワーキングメモリを評価する神経心理学的検査の成績向上（近位転移効果）が認められた。一方で、異なる認知機能を評価する検査の成績（遠位転移効果）は症例によりばらつくことが確認された。 今後は研究分担者、研究協力者と連携して円滑な症例リクルートを目指していきたいと考えている。また、症例リクルートの状況を共有するための会議を頻回に開催し、できる限り早期に目標症例数を達成できるよう努めていきたい。
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2020/04 -2023/03 
    Author : THA KHIN KHIN
     
    Since changes in the cerebrospinal fluid (CSF) composition reflect the function and abnormalities of the central nervous system (CNS), biochemical analysis of CSF collected by lumbar puncture forms an essential investigation for diagnosing various CNS diseases and determining the effectiveness of treatment. This study aimed to analyze the CSF composition using MRI and investigate the possibility of establishing a noninvasive CSF analysis system. The sensitivity of electrical conductivity and chemical exchange saturation transfer (CEST) imaging for CSF analysis was tested, and the corresponding scan and image processing parameters were optimized. Finally, the performance was tested using clinical studies. The electrical conductivity and CEST imaging index, derived by MRI, correlated with CSF protein concentration and cell count, suggesting potential usefulness in the noninvasive assessment of CSF biochemical composition.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2019/04 -2022/03 
    Author : Sawamura Daisuke
     
    We developed a computer-based attention and working memory training program as a self-management training program for patients with Moyamoya disease and examined its effectiveness. The research flow consisted of the development of the training program, evaluation of its effectiveness in healthy subjects, and evaluation of its effectiveness in patients with Moyamoya disease. The results showed that both healthy subjects and patients with Moyamoya disease showed improved performance in neuropsychological tests after training. In addition, training-derived functional and structural alterations in the brain were observed. The results of this study demonstrate the effectiveness of cognitive training for patients with Moyamoya disease, and suggest the possibility of clinical application due to the simplicity of its introduction, which can be conducted under self-management.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2017/04 -2020/03 
    Author : Tha Khin Khin
     
    Electrical conductivity is a property of materials to conduct electric current. Different materials have different electrical conductivity values, ranging from almost zero (insulators) to several million siemens per meter (S/m) (conductors). Living tissues are also reported to have variable electrical conductivity values - fat and bone have lower values, whereas the cerebrospinal fluid (CSF) and blood have higher values. Tumors, especially malignant ones, are reported to have higher values than the normal tissues. This study aimed at the establishment of an MRI technique to noninvasively measure electrical conductivity of lung lesions and to evaluate the accuracy of this technique in distinguishing lung tumors. We established an MRI technique for noninvasive electrical conductivity measurement for lung lesions. Tumor contrast, which is a texture characteristic of electrical conductivity distribution, can be useful in distinguishing between benign and malignant lung tumors.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2016/04 -2020/03 
    Author : Norio Katoh
     
    The purpose of this study is to develop a method to identify radioresistance of liver cancers from imaging information before proton beam therapy and to establish personalized proton beam therapy for each patient. Analysis of clinical outcomes of radiotherapy for liver cancer has shown that tumors smaller than 2 cm rarely recur even when treated with high doses. Analysis of the association between ADC images of MRI before proton beam therapy and local recurrence of tumors larger than 2 cm suggests that tumors with low ADC values are more likely to recur and that ADC values are effective in predicting treatment efficacy before proton beam therapy. Considering that the selection of treatment with X-ray or proton beam therapy is necessary for personalized proton beam therapy for tumors smaller than 5 cm, we created a selection model and found three factors related to the tumors (size, location, and number of tumors) that are necessary to consider for the selection criteria.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2015/04 -2018/03 
    Author : Ikoma Katsunori
     
    We performed imaging of 123-I-Iomazenil SPECT (IMZ SPECT) and MRI diffusion imaging for 11 patients with neurobehavioral disability due to traumatic brain injury. We evaluated by comparing Diffusion Spectrum Imaging(DSI), which is one of diffusion images, between the patient group and the healthy control. As a result, several abnormalities were detected including normal region by conventional MRI. DSI may be able to visualize brain damage which can not be detected by conventional image inspection. We will analyze the relationship between IMZ SPECT and other diffusion images.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2014/04 -2017/03 
    Author : Tha KhinKhin
     
    Electrical conductivity is a property of a material to conduct electric current. Different materials are known to have different electrical conductivity values, ranging from almost zero (insulators) to several million siemens per meter (S/m) (conductors). Living tissues are also reported to have variable electrical conductivity values -- fat and bone have lower values, whereas the cerebrospinal fluid (CSF) and blood have higher values. Tumors, especially malignant ones, are reported to have higher values than the normal tissues. This study aimed at the establishment of noninvasive electrical conductivity measurement technique by using MRI and to evaluate the accuracy of this technique. It was observed that the noninvasive electrical conductivity measurement by MRI was highly repeatable and valid. In addition, the results suggested that information about electrical conductivity can be useful in distinguishing glioblastoma from lower grade gliomas.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research
    Date (from‐to) : 2012/04 -2015/03 
    Author : YAMAMOTO Toru, TSUTSUMI Kaori, THA Khin Khin
     
    To investigate the possibility of noninvasive MR detection of pathologic changes in protein concentration, we measured the protein concentration dependency of permittivity, longitudinal and transverse relaxation rate. The transverse relaxation rate showed most accurate dependency. We also measured the transverse relaxation rate of cerebrospinal fluid in lateral ventricle and showed enough accuracy to detect pathologic―bacterial meningitis etc.―changes of protein concentration by developing a method to derive pixels that are free from cerebrospinal fluid flow.
  • Japan Society for Promotion of Science：
    Date (from‐to) : 2012/04 -2015/03 
    Author : Toru Yamamoto, Khin Khin Tha
  • Japanese Society for Promotion of Science：Grant-in-aid
    Date (from‐to) : 2011/04 -2014/03 
    Author : Khin Khin Tha
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)
    Date (from‐to) : 2011 -2013 
    Author : THA KHIN KHIN, TERAE Satoshi, YABE Ichiro
     
    This study evaluated if the major diffusion tensor imaging (DTI) metrics of the brain and the spinal cord can become the quantitative metrics for noninvasive evaluation of intractable diseases of the central nervous system. Significant alterations in the major DTI metrics were observed in sporadic amyotrophic lateral sclerosis, multiple sclerosis, and neuromyelitis optica spectrum disorders, despite no abnormality on the routine MRI sequences. The abnormalities detected on DTI are thought to reflect axonal loss and/ or demyelination. In sporadic amyotrophic lateral sclerosis, the DTI abnormalities correlated strongly with the scores which determine disease severity or progression. In conclusion, DTI is considered a sensitive technique to detect the microstructural abnormalities of the brain and the spinal cord in the intractable diseases of the central nervous system; and can be used to noninvasively quantify the severity or progression of these diseases.
  • 賦活領域の微細構造解析
    Japan Society for Promotion of Science：
    Date (from‐to) : 2009/04 -2011/03 
    Author : Yamamoto T, Kida I, Tha KK
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2009 -2011 
    Author : YAMAMOTO Toru, KIDA Ikuhiro, THA Khin khin
     
    We performed the same fMRI(functional Magnetic Resonance Imaging) study for different head positions by tilting the volunteer's head and showed that the activation area is strongly influenced by the orientation of the draining vein from the activation focus where the neurons are activated. And we showed that the MR signal from the cortex capillary bed contains signal from interstitial fluid which may depend on oxygen concentration in tissue, and that the sum of the BOLD(Blood oxygenation level-dependent) signals from the activation focus correlates quantitatively with the sum of the peak-to-peak amplitude of the evoked potential responses.
  • The Japanese Society for Promotion of Science：
    Date (from‐to) : 2005/04 -2007/04 
    Author : Khin Khin Tha

Social Contribution

  • Tips for Neuroimage Interpretation
    Date (from-to) : 2019/02
    Role : Lecturer
    Sponser, Organizer, Publisher  : Radiological Society of North America
    Event, Program, Title : International Visiting Professor Program
  • Date (from-to) : 2019/02
    Role : Lecturer
    Sponser, Organizer, Publisher  : Radiological Society of North America
    Event, Program, Title : International Visiting Professor Program
  • Toxic & Metabolic Diseases of the CNS: How to Arrive at Correct and Timely Imaging Diagnosis
    Date (from-to) : 2019/02
    Role : Lecturer
    Sponser, Organizer, Publisher  : Radiological Society of North America
    Event, Program, Title : International Visiting Professor Program
  • Imaging Spectrum of Demyelinating & Neurodegenerative Diseases
    Date (from-to) : 2019/02
    Role : Lecturer
    Sponser, Organizer, Publisher  : Radiological Society of North America
    Event, Program, Title : International Visiting Professor Program
  • CT and MRI Findings in Infectious & Inflammatory Diseases of the CNS
    Date (from-to) : 2019/02
    Role : Lecturer
    Sponser, Organizer, Publisher  : Radiological Society of North America
    Event, Program, Title : International Visiting Professor Program
  • Stroke Imaging & Beyond
    Date (from-to) : 2019/02
    Role : Lecturer
    Sponser, Organizer, Publisher  : Radiological Society of North America
    Event, Program, Title : International Visiting Professor Program
  • The Role of CT & MRI in Traumatic Brain Injury
    Date (from-to) : 2019/02
    Role : Lecturer
    Sponser, Organizer, Publisher  : Radiological Society of North America
    Event, Program, Title : International Visiting Professor Program
  • Radiologic Neuroanatomy: Know the Anatomy to Know the Pathology
    Date (from-to) : 2019/02
    Role : Lecturer
    Sponser, Organizer, Publisher  : Radiological Society of North America
    Event, Program, Title : International Visiting Professor Program

Media Coverage

Academic Contribution

  • Representative (Physician section）
    Date (from-to) :2021/09/10-Today
    Role: Planning etc
    Type: Academic society etc
    Organizer, responsible person: Japanese Society of Magnetic Resonance in Medicine
  • Annual Meeting Program Committee
    Date (from-to) :2021/05/19-Today
    Role: Planning etc
    Type: Academic society etc
    Organizer, responsible person: International Society of Magnetic Resonance in Medicine
  • Member of Scientific Editorial Board
    Date (from-to) :2021/01/01-Today
    Role: Review
    Type: Peer review etc
    Organizer, responsible person: European Radiology
  • Date (from-to) :2024/09/21
    Role: Panel chair etc
    Type: Others
    Organizer, responsible person: Japanese Society of Magnetic Resonance in Medicine
  • Committee member, Regional Committee for Asia-Oceania
    Date (from-to) :2017/11/26-2021/11/28
    Role: Planning etc
    Type: Academic society etc
    Organizer, responsible person: Radiological Society of North America
  • Safety Committee Member
    Date (from-to) :2018/06-2021/05
    Role: Planning etc
    Type: Academic society etc
    Organizer, responsible person: International Society of Magnetic Resonance in Medicine
  • Member of Board of Editors
    Date (from-to) :-2020/07/31
    Role: Peer review
    Type: Peer review etc
    Organizer, responsible person: American Society of Neuroradiology
  • The 7th GI-CoRE Medical Science and Engineering Symposium (Poster Session)
    Date (from-to) :2019/08
    Role: Panel chair etc
    Type: Competition etc

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