論文

• A novel method for measurements of sleep/wake states, feeding and drinking behaviors using the tracking technique of 3D positions in freely moving mice
  Hamada T, Sutherland K, Ishikawa M, Saito J, Miyamoto N, Honma S, Shirato H, Honma K-I
  Biochemical and Biophysical Research Communications, 2024年07月, ［査読有り］
  英語, 研究論文（学術雑誌）
• Fully automatic software for detecting radiographic joint space narrowing progression in rheumatoid arthritis: phantom study and comparison with visual assessment
  Taichi Okino, Yafei Ou, Masayuki Ikebe, Kenichi Tamura, Kenneth Sutherland, Jun Fukae, Kazuhide Tanimura, Tamotsu Kamishima
  JAPANESE JOURNAL OF RADIOLOGY, 41, 5, 510, 520, 2023年05月
  英語, 研究論文（学術雑誌）
• Fully automatic software for detecting radiographic joint space narrowing progression in rheumatoid arthritis: phantom study and comparison with visual assessment.
  Taichi Okino, Yafei Ou, Masayuki Ikebe, Kenichi Tamura, Kenneth Sutherland, Jun Fukae, Kazuhide Tanimura, Tamotsu Kamishima
  Japanese journal of radiology, 41, 5, 510, 520, 2023年05月, ［国内誌］
  英語, 研究論文（学術雑誌）, PURPOSE: We have developed an in-house software equipped with partial image phase-only correlation (PIPOC) which can automatically quantify radiographic joint space narrowing (JSN) progression. The purpose of this study was to evaluate the software in phantom and clinical assessments. MATERIALS AND METHODS: In the phantom assessment, the software's performance on radiographic images was compared to the joint space width (JSW) difference using a micrometer as ground truth. A phantom simulating a finger joint was scanned underwater. In the clinical assessment, 15 RA patients were included. The software measured the radiological progression of the finger joints between baseline and the 52nd week. The cases were also evaluated with the Genant-modified Sharp score (GSS), a conventional visual scoring method. We also quantitatively assessed these joints' synovial vascularity (SV) on power Doppler ultrasonography (0, 8, 20 and 52 weeks). RESULTS: In the phantom assessment, the PIPOC software could detect changes in JSN with a smallest detectable difference of 0.044 mm at 0.1 mm intervals. In the clinical assessment, the JSW change of the joints with GSS progression detected by the software was significantly greater than those without GSS progression (p = 0.004). The JSW change of joints with positive SV at baseline was significantly higher than those with negative SV (p = 0.024). CONCLUSION: Our in-house software equipped with PIPOC can automatically and quantitatively detect slight radiographic changes of JSW in clinically inactive RA patients.
• 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, 41, Suppl., 10, 10, (公社)日本医学放射線学会, 2023年02月
  日本語
• A real-time measurement system for gene expression rhythms from deep tissues of freely moving mice under light-dark conditions.
  Nakaya M, Wakamatsu M, Motegi H, Ami Tanaka A, Sutherland K, Ishikawa M, Ozaki M, Shirato H, Hamada K, Hamada T* (* Correspondence).
  Biochemistry and Biophysics Reports, 32, 101344, 101344, 2022年09月, ［査読有り］, ［国際誌］
  英語, 研究論文（学術雑誌）, Clock gene expression in most organs of the living body exhibits a diurnal rhythm synchronized with the external 24 h light-dark (LD) cycle via circadian pacemaker suprachiasmatic nucleus (SCN). Disturbances in clock gene expression due to desynchronization of clock gene expression of the external LD cycle are risk factors for developing various diseases. Measuring the in vivo clock genes expression rhythm for a long duration under LD conditions can greatly contribute to understand the pathogenic mechanism of the disease caused by the disturbance of the biological rhythm. However, it is presently difficult to continuously measure gene expression for a long duration under LD conditions. In present study, we succeeded in measuring Period1 (Per1) gene expression under LD conditions using ultraviolet (UV) light with filter cut the visible light range. In addition, we succeeded in measuring the kinetic change of liver Per1 gene expression during the process of desynchronization of behavioral rhythm from the LD cycle by chronic administration of methamphetamine (MAP). In the future, by using this system to measure clock gene expression rhythms of brain tissues such as SCN and peripheral tissues under LD conditions, it could contribute to understand the onset mechanism of diseases induced by the desynchronization mechanism of biological rhythm to the LD cycle.
• Period1 gene expression in the olfactory bulb and liver of freely moving streptozotocin-treated diabetic mouse.
  Harumi Kanou, Kouki Nagasawa, Yuki Ishii, Aya Chishima, Juri Hayashi, Sanae Haga, Kenneth Sutherland, Masayori Ishikawa, Michitaka Ozaki, Hiroki Shirato, Kazuko Hamada, Toshiyuki Hamada
  Biochemical and biophysical research communications, 560, 14, 20, 2021年06月30日, ［国際誌］
  英語, 研究論文（学術雑誌）, Clock genes express circadian rhythms in most organs. These rhythms are organized throughout the whole body, regulated by the suprachiasmatic nucleus (SCN) in the brain. Disturbance of these clock gene expression rhythms is a risk factor for diseases such as obesity. In the present study, to explore the role of clock genes in developing diabetes, we examined the effect of streptozotocin (STZ)-induced high glucose on Period1 (Per1) gene expression rhythm in the liver and the olfactory bub (OB) in the brain. We found a drastic increase of Per1 expression in both tissues after STZ injection while blood glucose content was low. After a rapid expression peak, Per1 expression showed no rhythm. Associated with an increase of glucose content, behavior became arrhythmic. Finally, we succeeded in detecting an increase of Per1 expression in mice hair follicles on day 1 after STZ administration, before the onset of symptoms. These results show that elevated Per1 expression by STZ plays an important role in the aggravation of diabetes.
• Stability of d-luciferin for bioluminescence to detect gene expression in freely moving mice for long durations.
  Kanako Nakajima, Kazuko Hamada, Ryoga Ito, Yukina Yoshida, Kenneth Sutherland, Masayori Ishikawa, Michitaka Ozaki, Hiroki Shirato, Toshiyuki Hamada
  Luminescence : the journal of biological and chemical luminescence, 36, 1, 94, 98, 2021年02月, ［国際誌］
  英語, 研究論文（学術雑誌）, Circadian disturbance of clock gene expression is a risk factor for diseases such as obesity, cancer, and sleep disorders. To study these diseases, it is necessary to monitor and analyze the expression rhythm of clock genes in the whole body for a long duration. The bioluminescent reporter enzyme firefly luciferase and its substrate d-luciferin have been used to generate optical signals from tissues in vivo with high sensitivity. However, little information is known about the stability of d-luciferin to detect gene expression in living animals for a long duration. In the present study, we examined the stability of a luciferin solution over 21 days. l-Luciferin, which is synthesized using racemization of d-luciferin, was at high concentrations after 21 days. In addition, we showed that bioluminescence of Period1 (Per1) expression in the liver was significantly decreased compared with the day 1 solution, although locomotor activity rhythm was not affected. These results showed that d-luciferin should be applied to the mouse within, at most, 7 days to detect bioluminescence of Per1 gene expression rhythm in vivo.
• Mouse period1 gene expression recording from olfactory bulb under free moving conditions with a portable optic fibre device.
  Ryoga Ito, Kazuko Hamada, Shigeru Kasahara, Yoshihiro Kikuchi, Kanako Nakajima, Kenneth Sutherland, Hiroki Shirato, Michitaka Ozaki, Masayori Ishikawa, Toshiyuki Hamada
  Luminescence : the journal of biological and chemical luminescence, 35, 8, 1248, 1253, 2020年12月, ［国際誌］
  英語, 研究論文（学術雑誌）, Because the disruption of circadian clock gene is a risk factor in many diseases such as obesity and cancer, it is important to monitor and analyzed the expression of the rhythm of the clock gene throughout the body over a long period of time. Although we previously reported on a new gene expression analysis system tracking a target position on the body surface of freely moving mice, the experimental apparatus required a large space. We have therefore developed an in vivo recording system using a portable photomultiplier tube (PMT) system attached to an optical fibre. Directly connecting the target area with the device, we could easily measure the photon counts in a very small space. However, little information is known about the characteristics of optical fibres when exposed to twisting/looping in association with a moving mouse and the effect of the surface of optical fibre. In the present study, we report on the characteristics of optical fibres to detect gene expression rhythm in freely moving mice. Using this portable optical device directly connected with a target area, we were able to measure the circadian rhythm of clock gene expression over a prolonged period in freely moving mice in a small space.
• Fully automatic quantitative software for assessment of minute finger joint space narrowing progression on radiographs: evaluation in rheumatoid arthritis patients with long-term sustained clinical low disease activity.
  Kazuki Kato, Kenneth Sutherland, Yuki Tanaka, Masaru Kato, Jun Fukae, Kazuhide Tanimura, Tamotsu Kamishima
  Japanese journal of radiology, 38, 10, 979, 986, 2020年10月, ［国内誌］
  英語, 研究論文（学術雑誌）, PURPOSE: Rheumatoid arthritis (RA) causes joint space narrowing (JSN) as a form of joint destruction. We developed an automatic system that can detect joint locations and compute the joint space difference index (JSDI), which was defined as the chronological change in JSN between two radiographs. This study aims to evaluate the application of "machine vision" for radiographic image of the finger joints. MATERIALS AND METHODS: Fifteen RA patients with long-term sustained clinical low disease activity were recruited. All patients underwent hand radiography and power Doppler ultrasonography (PDUS). The JSN was evaluated using the Genant-modified Sharp scoring (GSS) method and the automatic system. Synovial vascularity (SV) was assessed quantitatively using ultrasonography. RESULTS: There were no significant differences in the JSDI between the joints with JSN and those without JSN on GSS (p = 0.052). The JSDI of the joints with SV was significantly higher than those without SV (p = 0.043). The JSDI of the no therapeutic response group was significantly higher than those of the response group (p < 0.001). CONCLUSION: Our software can automatically evaluate temporal changes of JSN, which might free rheumatologists / radiologists from the burden of scoring hand radiography.
• Double recording system of Period1 gene expression rhythm in the olfactory bulb and liver in freely moving mouse.
  Kazuko Hamada, Akari Oota, Ryoga Ito, Shigeru Kasahara, Kanako Nakajima, Yoshihiro Kikuchi, Kenneth Sutherland, Masayori Ishikawa, Hiroki Shirato, Michitaka Ozaki, Toshiyuki Hamada
  Biochemical and biophysical research communications, 529, 4, 898, 903, 2020年09月03日, ［国際誌］
  英語, 研究論文（学術雑誌）, Clock genes express circadian rhythms in most organs. These rhythms are organized throughout the whole body, regulated by the suprachiasmatic nucleus (SCN) in the brain. Disturbance of these clock gene expression rhythms is a risk factor for diseases such as obesity and cancer. To understand the mechanism of regulating clock gene expression rhythms in vivo, multiple real time recording systems are required. In the present study, we developed a double recording system of Period1 expression rhythm in peripheral tissue (liver) and the brain. In peripheral tissue, quantification of gene expression in a steadily moving target was achieved by using a photomultiplier tube (PMT) attached to a tissue contact optical sensor (TCS). Using this technique, we were able to analyze circadian rhythms of clock gene expression over a prolonged period in the liver and olfactory bub (OB) of the brain. The present double recording system has no effect on behavioral activity or rhythm. Our novel system thus successfully quantifies clock gene expression in deep areas of the body in freely moving mice for a period sufficient to analyze circadian dynamics. In addition, our double recording system can be widely applied to many areas of biomedical research, as well as applications beyond medicine.
• Quick and accurate selection of hand images among radiographs from various body parts using deep learning.
  Kohei Fujiwara, Wanxuan Fang, Taichi Okino, Kenneth Sutherland, Akira Furusaki, Akira Sagawa, Tamotsu Kamishima
  Journal of X-ray science and technology, 28, 6, 1199, 1206, 2020年, ［国際誌］
  英語, 研究論文（学術雑誌）, BACKGROUND: Although rheumatoid arthritis (RA) causes destruction of articular cartilage, early treatment significantly improves symptoms and delays progression. It is important to detect subtle damage for an early diagnosis. Recent software programs are comparable with the conventional human scoring method regarding detectability of the radiographic progression of RA. Thus, automatic and accurate selection of relevant images (e.g. hand images) among radiographic images of various body parts is necessary for serial analysis on a large scale. OBJECTIVE: In this study we examined whether deep learning can select target images from a large number of stored images retrieved from a picture archiving and communication system (PACS) including miscellaneous body parts of patients. METHODS: We selected 1,047 X-ray images including various body parts and divided them into two groups: 841 images for training and 206 images for testing. The training images were augmented and used to train a convolutional neural network (CNN) consisting of 4 convolution layers, 2 pooling layers and 2 fully connected layers. After training, we created software to classify the test images and examined the accuracy. RESULTS: The image extraction accuracy was 0.952 and 0.979 for unilateral hand and both hands, respectively. In addition, all 206 test images were perfectly classified into unilateral hand, both hands, and the others. CONCLUSIONS: Deep learning showed promise to enable efficiently automatic selection of target X-ray images of RA patients.
• Intravoxel incoherent motion MRI for discrimination of synovial proliferation in the hand arthritis: A prospective proof-of-concept study.
  Motoshi Fujimori, Koichi Murakami, Hiroyuki Sugimori, Yutong Lu, Kenneth Sutherland, Nozomi Oki, Takatoshi Aoki, Tamotsu Kamishima
  Journal of magnetic resonance imaging : JMRI, 50, 4, 1199, 1206, 2019年10月, ［査読有り］, ［国際誌］
  英語, 研究論文（学術雑誌）
• Detection of Fine Radiographic Progression in Finger Joint Space Narrowing Beyond Human Eyes: Phantom Experiment and Clinical Study with Rheumatoid Arthritis Patients.
  Kazuki Kato, Nobutoshi Yasojima, Kenichi Tamura, Shota Ichikawa, Kenneth Sutherland, Masaru Kato, Jun Fukae, Kazuhide Tanimura, Yuki Tanaka, Taichi Okino, Yutong Lu, Tamotsu Kamishima
  Scientific reports, 9, 1, 8526, 8526, 2019年06月12日, ［国際誌］
  英語, 研究論文（学術雑誌）, The visual assessment of joint space narrowing (JSN) on radiographs of rheumatoid arthritis (RA) patients such as the Genant-modified Sharp score (GSS) is widely accepted but limited by its subjectivity and insufficient sensitivity. We developed a software application which can assess JSN quantitatively using a temporal subtraction technique for radiographs, in which the chronological change in JSN between two radiographs was defined as the joint space difference index (JSDI). The aim of this study is to prove the superiority of the software in terms of detecting fine radiographic progression in finger JSN over human observers. A micrometer measurement apparatus that can adjust arbitrary joint space width (JSW) in a phantom joint was developed to define true JSW. We compared the smallest detectable changes in JSW between the JSDI and visual assessment using phantom images. In a clinical study, 222 finger joints without interval score change on GSS in 15 RA patients were examined. We compared the JSDI between joints with and without synovial vascularity (SV) on power Doppler ultrasonography during the follow-up period. True JSW difference was correlated with JSDI for JSW differences ranging from 0.10 to 1.00 mm at increments of 0.10 mm (R2 = 0.986 and P < 0.001). Rheumatologists were difficult to detect JSW difference of 0.30 mm or less. The JSDI of finger joints with SV was significantly higher than those without SV (P = 0.030). The software can detect fine differences in JSW that are visually unrecognizable.
• 3D Transformation Matrix Calculation and Pixel Intensity Normalization for the Dual Focus Tracking System　　　　　　　　　　　　　　　
  Kenneth Sutherland, Toshiyuki Hamada, Masayori Ishikawa, Naoki Miyamoto, Masahiro Mizuta, Hiroyuki Date, Hiroki Shirato
  Journal of Medical and Biological Engineering, 2019年, ［査読有り］
  英語, 研究論文（学術雑誌）
• Investigation of energy absorption by clustered gold nanoparticles
  Jihun Kwon, Kenneth Sutherland, Anastasia Makarova, Taeko Matsuura, Takayuki Hashimoto, Hao Peng, Toshiyuki Toshito, Kikuo Umegaki, Hiroki Shirato, Shinichi Shimizu
  Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms, 429, 34, 41, 2018年08月15日, ［査読有り］
  研究論文（学術雑誌）
• Composite assessment of power Doppler ultrasonography and MRI in rheumatoid arthritis: a pilot study of predictive value in radiographic progression after one year.
  Fujimori M, Kamishima T, Kato M, Seno Y, Sutherland K, Sugimori H, Nishida M, Atsumi T
  The British journal of radiology, 91, 1086, 20170748, 20170748, 2018年06月, ［査読有り］, ［国際誌］
  英語, 研究論文（学術雑誌）, OBJECTIVE: Power Doppler ultrasonography (PDUS) and MRI are independently useful to predict structural damage in patients with rheumatoid arthritis (RA). We hypothesize that there is a complementary relationship between these modalities. The aim of this study is, therefore, to investigate the usefulness of the predictive value of composite assessment of PDUS and contrast-enhanced MRI in radiographic outcomes in patients with RA. METHODS: 20 patients (17 females and 3 males) with RA on disease-modifying antirheumatic drugs underwent PDUS and MRI of both hands at baseline. Radiography of the bilateral hands was performed at baseline and at 1 year. Articular synovitis on PDUS was evaluated according to quantitative measurement. Synovitis, bone marrow edema and bone erosion were scored according to the RA MRI scoring method. The changes of joint space narrowing and bone erosion on radiograph were assessed by the Sharp/van der Heijde method. We applied t-statistics to combine the assessment of quantitative PDUS with semiquantitative MRI. RESULTS: Structural damage progression for radiography was not correlated with any evaluations for MRI, while it showed significant correlation with synovitis on PDUS (rs = 0.597, p = 0.005). The composite assessment of both modalities (synovitis for PDUS and bone marrow edema for MRI) was correlated with structural damage progression on radiograph (rs = 0.792, p < 0.0001). CONCLUSION: Composite assessment of PDUS and MRI may have a stronger predictive value in radiographic progression than PDUS or MRI alone in RA. Advances in knowledge: Composite assessment of PDUS and MRI may be an effective predictor of structural damage in RA.
• Quantification of hand synovitis in rheumatoid arthritis: Arterial mask subtraction reinforced with mutual information can improve accuracy of pixel-by-pixel time-intensity curve shape analysis in dynamic MRI.
  Kobayashi Y, Kamishima T, Sugimori H, Ichikawa S, Noguchi A, Kono M, Iiyama T, Sutherland K, Atsumi T
  Journal of magnetic resonance imaging : JMRI, 2018年03月, ［査読有り］, ［国際誌］
  英語, 研究論文（学術雑誌）, BACKGROUND: Synovitis, which is a hallmark of rheumatoid arthritis (RA), needs to be precisely quantified to determine the treatment plan. Time-intensity curve (TIC) shape analysis is an objective assessment method for characterizing the pixels as artery, inflamed synovium, or other tissues using dynamic contrast-enhanced MRI (DCE-MRI). PURPOSE/HYPOTHESIS: To assess the feasibility of our original arterial mask subtraction method (AMSM) with mutual information (MI) for quantification of synovitis in RA. STUDY TYPE: Prospective study. SUBJECTS: Ten RA patients (nine women and one man; mean age, 56.8 years; range, 38-67 years). FIELD STRENGTH/SEQUENCE: 3T/DCE-MRI. ASSESSMENT: After optimization of TIC shape analysis to the hand region, a combination of TIC shape analysis and AMSM was applied to synovial quantification. The MI between pre- and postcontrast images was utilized to determine the arterial mask phase objectively, which was compared with human subjective selection. The volume of objectively measured synovitis by software was compared with that of manual outlining by an experienced radiologist. Simple TIC shape analysis and TIC shape analysis combined with AMSM were compared in slices without synovitis according to subjective evaluation. STATISTICAL TESTS: Pearson's correlation coefficient, paired t-test and intraclass correlation coefficient (ICC). RESULTS: TIC shape analysis was successfully optimized in the hand region with a correlation coefficient of 0.725 (P < 0.01) with the results of manual assessment regarded as ground truth. Objective selection utilizing MI had substantial agreement (ICC = 0.734) with subjective selection. Correlation of synovial volumetry in combination with TIC shape analysis and AMSM with manual assessment was excellent (r = 0.922, P < 0.01). In addition, negative predictive ability in slices without synovitis pixels was significantly increased (P < 0.01). DATA CONCLUSIONS: The combination of TIC shape analysis and image subtraction reinforced with MI can accurately quantify synovitis of RA in the hand by eliminating arterial pixels. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018.
• Power Doppler signal calibration in the finger joint between two models of ultrasound machine: a pilot study using a phantom and joints in patients with rheumatoid arthritis.
  Ryosuke Sakano, Katsumi Saito, Tamotsu Kamishima, Mutsumi Nishida, Tatsunori Horie, Atsushi Noguchi, Michihito Kono, Kenneth Sutherland, Tatsuya Atsumi
  Acta radiologica (Stockholm, Sweden : 1987), 58, 10, 1238, 1244, 2017年10月, ［査読有り］, ［国際誌］
  英語, 研究論文（学術雑誌）
• Computer-Based Radiographic Quantification of Joint Space Narrowing Progression Using Sequential Hand Radiographs: Validation Study in Rheumatoid Arthritis Patients from Multiple Institutions
  Shota Ichikawa, Tamotsu Kamishima, Kenneth Sutherland, Jun Fukae, Kou Katayama, Yuko Aoki, Takanobu Okubo, Taichi Okino, Takahiko Kaneda, Satoshi Takagi, Kazuhide Tanimura
  JOURNAL OF DIGITAL IMAGING, 30, 5, 648, 656, 2017年10月, ［査読有り］
  英語, 研究論文（学術雑誌）
• Cartilage quantification using contrast-enhanced MRI in the wrist of rheumatoid arthritis: cartilage loss is associated with bone marrow edema.
  Motoshi Fujimori, Satoko Nakamura, Kiminori Hasegawa, Kunihiro Ikeno, Shota Ichikawa, Kenneth Sutherland, Tamotsu Kamishima
  The British journal of radiology, 90, 1077, 20170167, 20170167, 2017年08月, ［査読有り］, ［国際誌］
  英語, 研究論文（学術雑誌）
• Visceral adipose tissue area measurement at a single level: can it represent visceral adipose tissue volume?
  Yusuke Noumura, Tamotsu Kamishima, Kenneth Sutherland, Hideho Nishimura
  The British journal of radiology, 90, 1077, 20170253, 20170253, 2017年08月, ［査読有り］, ［国際誌］
  英語, 研究論文（学術雑誌）
• Semi-Automated Quantification of Finger Joint Space Narrowing Using Tomosynthesis in Patients with Rheumatoid Arthritis
  Shota Ichikawa, Tamotsu Kamishima, Kenneth Sutherland, Hideki Kasahara, Yuka Shimizu, Motoshi Fujimori, Nobutoshi Yasojima, Yohei Ono, Takahiko Kaneda, Takao Koike
  JOURNAL OF DIGITAL IMAGING, 30, 3, 369, 375, 2017年06月, ［査読有り］
  英語, 研究論文（学術雑誌）
• A reliability study using computer-based analysis of finger joint space narrowing in rheumatoid arthritis patients.
  Katsuya Hatano, Tamotsu Kamishima, Kenneth Sutherland, Masaru Kato, Ikuma Nakagawa, Shota Ichikawa, Keisuke Kawauchi, Shota Saitou, Masaya Mukai
  Rheumatology international, 37, 2, 189, 195, 2017年02月, ［査読有り］, ［国際誌］
  英語, 研究論文（学術雑誌）
• Pixel-by-Pixel Arterial Spin Labeling Blood Flow Pattern Variation Analysis for Discrimination of Rheumatoid Synovitis: A Pilot Study.
  Taro Sakashita, Tamotsu Kamishima, Hiroyuki Sugimori, Minghui Tang, Atsushi Noguchi, Michihito Kono, Kenneth Sutherland, Tatsuya Atsumi
  Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine, 16, 1, 78, 83, 2017年01月10日, ［査読有り］, ［国内誌］
  英語, 研究論文（学術雑誌）
• Performance of computer-based analysis using temporal subtraction to assess joint space narrowing progression in rheumatoid patients
  Shota Ichikawa, Tamotsu Kamishima, Kenneth Sutherland, Takanobu Okubo, Kou Katayama
  RHEUMATOLOGY INTERNATIONAL, 36, 1, 101, 108, 2016年01月, ［査読有り］
  英語, 研究論文（学術雑誌）
• Tomosynthesis can facilitate accurate measurement of joint space width under the condition of the oblique incidence of X-rays in patients with rheumatoid arthritis
  Yohei Ono, Rina Kashihara, Nobutoshi Yasojima, Hideki Kasahara, Yuka Shimizu, Kenichi Tamura, Kaori Tsutsumi, Kenneth Sutherland, Takao Koike, Tamotsu Kamishima
  BRITISH JOURNAL OF RADIOLOGY, 89, 1062, 20150967, 2016年, ［査読有り］
  英語, 研究論文（学術雑誌）
• Radiographic quantifications of joint space narrowing progression by computer-based approach using temporal subtraction in rheumatoid wrist
  Shota Ichikawa, Tamotsu Kamishima, Kenneth Sutherland, Takanobu Okubo, Kou Katayama
  BRITISH JOURNAL OF RADIOLOGY, 89, 1057, 20150403, 2016年, ［査読有り］
  英語, 研究論文（学術雑誌）
• Accurate quantitative assessment of synovitis in rheumatoid arthritis using pixel-by-pixel, time-intensity curve shape analysis
  Taro Sakashita, Tamotsu Kamishima, Yuto Kobayashi, Hiroyuki Sugimori, Minghui Tang, Kenneth Sutherland, Atsushi Noguchi, Michihito Kono, Tatsuya Atsumi
  BRITISH JOURNAL OF RADIOLOGY, 89, 1061, 20151000, 2016年, ［査読有り］
  英語, 研究論文（学術雑誌）
• Dose distribution of electrons from gold nanoparticles by proton beam irradiation　　　　　　　　　　　　　　　
  Jihun Kwon, Kenneth Sutherland, Takayuki Hashimoto, Hiroyuki Date
  International Journal of Medical Physics, Clinical Engineering and Radiation Oncology, 2015, 4, 49, 53, 2015年, ［査読有り］
  英語, 研究論文（学術雑誌）
• Development of a wavelength-separated type scintillator with optical fiber dosimeter to compensate for the Cerenkov radiation effect
  Masayori Ishikawa, Naomi Nagase, Taeko Matsuura, Junichi Hiratsuka, Ryusuke Suzuki, Naoki Miyamoto, Kenneth Sutherland, Katsuhisa Fujita, Hiroki Shirato
  Journal of Radiation Research, 56, 2, 372, 381, Oxford University Press, 2015年, ［査読有り］
  英語, The scintillator with optical fiber (SOF) dosimeter consists of a miniature scintillator mounted on the tip of an optical fiber. The scintillator of the current SOF dosimeter is a 1-mm diameter hemisphere. For a scintillation dosimeter coupled with an optical fiber, measurement accuracy is influenced by signals due to Cerenkov radiation in the optical fiber. We have implemented a spectral filtering technique for compensating for the Cerenkov radiation effect specifically for our plastic scintillator-based dosimeter, using a wavelength-separated counting method. A dichroic mirror was used for separating input light signals. Individual signal counting wasperformed for high- and low-wavelength light signals. To confirm the accuracy, measurements with variousamounts of Cerenkov radiation were performed by changing the incident direction while keeping the Ir-192 source-to-dosimeter distance constant, resulting in a fluctuation of <5%. Optical fiber bending was alsoaddressed; no bending effect was observed for our wavelength-separated SOF dosimeter.
• 教育講座－モンテカルロシミュレーションの放射線技術への利用－３．モンテカルロシミュレーションの放射線医療への応用　　　　　　　　　　　　　　　
  ケネス・サザランド, 白石 祐太, 伊達 広行
  日本放射線技術学会雑誌, 70, 8, 827, 838, 2014年08月, ［招待有り］
  日本語, 研究論文（学術雑誌）
• 一方向X線透視による低被曝・省スペース型動体追跡装置の開発
  宮本直樹, 石川正純, SUTHERLAND Kenneth, 鈴木隆介, 松浦妙子, 高尾聖心, 寅松千枝, 二本木英明, 清水伸一, 梅垣菊男, 白土博樹
  医学物理 Supplement, 32, 3, 281, 282, 2012年09月13日
  日本語
• 体内複数マーカを用いた高精度ゲーティング照射法の基礎検討
  大友可奈子, 宮本直樹, SUTHERLAND Kenneth, 鈴木隆介, 松浦妙子, 鬼丸力也, 清水伸一, 梅垣菊男, 白土博樹, 石川正純
  医学物理 Supplement, 32, 3, 155, 156, 2012年09月13日
  日本語
• 陽子線スキャニング照射における体内マーカーによる線量遮蔽のTCPを用いた評価
  前田憲一郎, 松浦妙子, 高尾聖心, SUTHERLAND Kenneth, 寅松千枝, 二本木英明, 宮本直樹, 石川正純, 清水伸一, 梅垣菊男, 白土博樹
  医学物理 Supplement, 32, 3, 101, 102, 2012年09月13日
  日本語
• Biological effect of dose distortion by fiducial markers in spot-scanning proton therapy with a limited number of fields: a simulation study.
  Matsuura T, Maeda K, Sutherland K, Takayanagi T, Shimizu S, Takao S, Miyamoto N, Nihongi H, Toramatsu C, Nagamine Y, Fujimoto R, Suzuki R, Ishikawa M, Umegaki K, Shirato H
  Medical physics, 39, 9, 5584, 5591, 9, 2012年09月, ［査読有り］
  英語, Purpose: In accurate proton spot-scanning therapy, continuous target tracking by fluoroscopic X-ray during irradiation is beneficial not only for respiratory moving tumors of lung and liver but also for relatively stationary tumors of prostate. Implanted gold markers have been used with great effect for positioning the target volume by a fluoroscopy, especially for the cases of liver and prostate with the targets surrounded by water-equivalent tissues. However, recent studies have revealed that gold markers can cause a significant underdose in proton therapy. This paper focuses on prostate cancer and explores the possibility that multiple-field irradiation improves the underdose effect by markers on Tumor-Control Probability (TCP). Methods: A Monte Carlo simulation was performed to evaluate the dose distortion effect. A spherical gold marker was placed at several characteristic points in a water phantom. Markers were with two different diameters of 2 mm and 1.5 mm, both visible on fluoroscopy. Three beam arrangements of SFUD (single-field uniform dose) were examined: one lateral field, two opposite lateral fields, and three fields (two opposite lateral fields + anterior field). The Relative Biological Effectiveness (RBE) was set to 1.1 and a dose of 74 Gy (RBE) was delivered to the target of a typical prostate size in 37 fractions. The ratios of TCP to that without the marker (TCPr) were compared with the parameters of the marker sizes, number of fields, and marker positions. To take into account the dependence of biological parameters in TCP model, α/β values of 1.5, 3, and 10 Gy (RBE) were considered. Results: It was found that the marker of 1.5 mm diameter does not affect the TCPs with all α/β values when two or more fields are used. On the other hand, if the marker diameter is φ2 mm, more than two irradiation fields are required to suppress the decrease in TCP from TCPr by less than 3%. This is especially true when multiple (two or three) markers are used for alignment of a patient. Conclusions: It is recommended that φ1.5 mm markers be used to avoid the reduction of TCP as well as to spare the surrounding critical organs, as long as the markers are visible on X-ray fluoroscopy. When φ2 mm markers are implanted, more than two fields should be used and the markers should not be placed close to the distal edge of any of the beams.
• Improvement of tracking accuracy and stability by recursive image processing in real-time tumor-tracking radiotherapy system
  Miyamoto Naoki, Sutherland Kenneth, Suzuki Ryusuke, Matsuura Taeko, Toramatsu Chie, Takao Seishin, Nihongi Hideaki, Kinoshita Rumiko, Shimizu Shinichi, Onimaru Rikiya, Umegaki Kikuo, Shirato Hiroki, Ishikawa Masayori
  MEDICAL IMAGING 2012: IMAGE-GUIDED PROCEDURES, ROBOTIC INTERVENTIONS, AND MODELING, 8316, 83160, 2012年, ［査読有り］
  研究論文（国際会議プロシーディングス）
• Optimization of fluoroscopy parameters using pattern matching prediction in the real-time tumor-tracking radiotherapy system.
  Miyamoto N, Ishikawa M, Bengua G, Sutherland K, Suzuki R, Kimura S, Shimizu S, Onimaru R, Shirato H
  Physics in medicine and biology, 56, 15, 4803, 4813, 15, 2011年08月, ［査読有り］, ［国際誌］
  英語, 研究論文（学術雑誌）, In the real-time tumor-tracking radiotherapy system, fluoroscopy is used to determine the real-time position of internal fiducial markers. The pattern recognition score (PRS) ranging from 0 to 100 is computed by a template pattern matching technique in order to determine the marker position on the fluoroscopic image. The PRS depends on the quality of the fluoroscopic image. However, the fluoroscopy parameters such as tube voltage, current and exposure duration are selected manually and empirically in the clinical situation. This may result in an unnecessary imaging dose from the fluoroscopy or loss of the marker because of too much or insufficient x-ray exposure. In this study, a novel optimization method is proposed in order to minimize the fluoroscopic dose while keeping the image quality usable for marker tracking. The PRS can be predicted in a region where the marker appears to move in the fluoroscopic image by the proposed method. The predicted PRS can be utilized to judge whether the marker can be tracked with accuracy. In this paper, experiments were performed to show the feasibility of the PRS prediction method under various conditions. The predicted PRS showed good agreement with the measured PRS. The root mean square error between the predicted PRS and the measured PRS was within 1.44. An experiment using a motion controller and an anthropomorphic chest phantom was also performed in order to imitate a clinical fluoroscopy situation. The result shows that the proposed prediction method is expected to be applicable in a real clinical situation.
• A feasibility study of a molecular-based patient setup verification method using a parallel-plane PET system.
  Yamaguchi S, Ishikawa M, Bengua G, Sutherland K, Nishio T, Tanabe S, Miyamoto N, Suzuki R, Shirato H
  Physics in medicine and biology, 56, 4, 965, 977, 4, 2011年02月, ［査読有り］
  英語, A feasibility study of a novel PET-based molecular image guided radiation therapy (m-IGRT) system was conducted by comparing PET-based registration with radiographic registration. We selected a pair of opposing parallel-plane PET systems for the practical implementation. Five different sizes of 18F cylindrical sources (diameter: 8, 12, 16, 24, 32 mm) were used to determine setup errors. PET data acquisition times were 1, 3 and 5 min. Image registration was performed by 5 observers. Setup errors from the PET system were compared with setup errors from image intensifier-based fluoroscopy. The in-plane and cross-plane FWHM of the profile of a 2 mm diameter sources for the parallel-plane PET system were approximately 1.8 mm and 8.1 mm, respectively. The majority of the mean registration errors obtained from the PET-based registration were not significantly different from those obtained from the radiographic registration. Acquisition time did not appear to result in significant differences in the mean registration error. The mean registration error for the PET-based registration was found to be 0.93±0.33 mm. This is not statistically different from the radiographic registration which had mean registration error of 0.92±0.27 mm. Our results suggest that m-IGRT is feasible for clinical use with a parallel plane PET-based registration.
• Detection of patient setup errors with a portal image - DRR registration software application
  Kenneth Sutherland, Masayori Ishikawa, Gerard Bengua, Yoichi M. Ito, Yoshiko Miyamoto, Hiroki Shirato
  JOURNAL OF APPLIED CLINICAL MEDICAL PHYSICS, 12, 3, 2, 15, 2011年, ［査読有り］
  英語, 研究論文（学術雑誌）

  
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• Optimization of fluoroscopy parameters using pattern matching prediction in the real-time tumor-tracking radiotherapy system.
  Miyamoto N, Ishikawa M, Bengua G, Sutherland K, Suzuki R, Kimura S, Shimizu S, Onimaru R, Shirato H
  Phys Med Biol, 56, 15, 4803, 13, 2011年, ［査読有り］, ［国際誌］
  英語, 研究論文（学術雑誌）, In the real-time tumor-tracking radiotherapy system, fluoroscopy is used to determine the real-time position of internal fiducial markers. The pattern recognition score (PRS) ranging from 0 to 100 is computed by a template pattern matching technique in order to determine the marker position on the fluoroscopic image. The PRS depends on the quality of the fluoroscopic image. However, the fluoroscopy parameters such as tube voltage, current and exposure duration are selected manually and empirically in the clinical situation. This may result in an unnecessary imaging dose from the fluoroscopy or loss of the marker because of too much or insufficient x-ray exposure. In this study, a novel optimization method is proposed in order to minimize the fluoroscopic dose while keeping the image quality usable for marker tracking. The PRS can be predicted in a region where the marker appears to move in the fluoroscopic image by the proposed method. The predicted PRS can be utilized to judge whether the marker can be tracked with accuracy. In this paper, experiments were performed to show the feasibility of the PRS prediction method under various conditions. The predicted PRS showed good agreement with the measured PRS. The root mean square error between the predicted PRS and the measured PRS was within 1.44. An experiment using a motion controller and an anthropomorphic chest phantom was also performed in order to imitate a clinical fluoroscopy situation. The result shows that the proposed prediction method is expected to be applicable in a real clinical situation.
• H&N癌のための18F‐フルオロミソニダゾールPETの影響とIMRTへの適用
  安田耕一, 長谷川雅一, 鬼丸力也, 木下留美子, 加藤徳雄, 田口大志, 清水伸一, 井上哲也, 小野寺俊輔, 溝口史樹, 青山英史, 白土博樹, 志賀哲, 岡本祥三, 玉木長良, 石川正純, SUTHERLAND Kenneth, BENGUA Gerard, 宮本直樹, 鈴木隆介
  Jpn J Radiol, 28, Supplement 1, 14, 2010年07月25日
  日本語
• 生物学的効果を考慮した治療計画—Dose Volume Histogram解析による考察—
  関原和正, 石川正純, SUTHERLAND Kenneth, BENGUA Gerard, 宮本直樹, 鈴木隆介, 清水伸一, 白土博樹
  Jpn J Radiol, 28, Supplement 1, 15, 2010年07月25日
  日本語
• Evaluation of the effectiveness of the stereotactic body frame in reducing respiratory intrafractional organ motion using the real-time tumor-tracking radiotherapy system.
  Bengua G, Ishikawa M, Sutherland K, Horita K, Yamazaki R, Fujita K, Onimaru R, Katoh N, Inoue T, Onodera S, Shirato H
  International journal of radiation oncology, biology, physics, 77, 630, 636, 2, 2010年06月, ［査読有り］
• A parameter study of pencil beam proton dose distributions for the treatment of ocular melanoma utilizing spot scanning
  Kenneth Sutherland, Satoshi Miyajima, Hiroyuki Date, Hiroki Shirato, Masayori Ishikawa, Masao Murakami, Mitsuru Yamagiwa, Paul Bolton, Toshiki Tajima
  Radiological Physics and Technology, 3, 1, 16, 22, 2010年01月, ［査読有り］
  英語, 研究論文（学術雑誌）

  
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• Evaluation of the effectiveness of the stereotactic body frame in reducing respiratory intrafractional organ motion using the real-time tumor-tracking radiotherapy system.
  Bengua G, Ishikawa M, Sutherland K, Horita K, Yamazaki R, Fujita K, Onimaru R, Katoh N, Inoue T, Onodera S, Shirato H
  Int J Radiat Oncol Biol Phys, 77, 2, 630, 6, 2010年, ［査読有り］
• 動体追跡装置におけるコントラスト‐ノイズ比の測定方法の検討
  木村傑, 宮本直樹, 石川正純, SUTHERLAND Kenneth, BENGUA Gerard, 鈴木隆介, 清水伸一, 青山英史, 鬼丸力也, 白土博樹
  医学物理 Supplement, 29, 3, 148-149, 2009年09月
  日本語
• 動体追跡装置を用いた肺定位照射時の投与線量解析—動体追跡データに基づくDVH解析—
  石川正純, サザランド ケネス, ベングア ジェラード, 鈴木隆介, 宮本直樹, 加藤徳雄, 清水伸一, 鬼丸力也, 青山英史, 白土博樹
  日本放射線腫よう学会誌, 21, Supplement 1, 158, 2009年08月19日
  日本語
• 体内臓器同期照射を目的とした次世代動体追跡装置の開発〜透視画像の歪みと位置計算誤差〜
  宮本直樹, SUTHERLAND Kenneth, 石川正純, 鈴木隆介, BENGUA Gerard, 木村傑, 清水伸一, 青山英史, 鬼丸力也, 白土博樹
  医学物理 Supplement, 29, 2, 192-193, 2009年04月
  日本語
• 体内臓器同期照射を目的とした次世代動体追跡装置の開発〜デジタル画像機器としての定量的評価〜
  木村傑, 石川正純, SUTHERLAND Kenneth, 宮本直樹, BENGUA Gerard, 鈴木隆介, 清水伸一, 青山英史, 鬼丸力也, 白土博樹
  医学物理 Supplement, 29, 2, 196-197, 2009年04月
  日本語
• 体内臓器同期照射を目的とした次世代動体追跡装置の開発〜複数マーカ追跡への挑戦〜
  石川正純, SUTHERLAND Kenneth, 宮本直樹, BENGUA Gerard, 清水伸一, 青山英史, 鬼丸力也, 木村傑, 白土博樹
  医学物理 Supplement, 29, 2, 194-195, 2009年04月
  日本語
• A feasibility study of novel plastic scintillation dosimetry with pulse counting mode
  M. Ishikawa, G. Bengua, K. Sutherland, J. Hiratsuka, N. Katoh, S. Shimizu, H. Aoyama, K. Fujita, R. Yamazaki, K. Horita, H. Shirato
  Physics in Medicine and Biology, 54, 2079, 2092, 2009年, ［査読有り］
• SOF線量計によるIr‐192高線量率密封小線源治療時のin‐vivoリアルタイム線量測定
  石川正純, 平塚純一, 長瀬尚巳, GERARD Bengua, KENNETH Sutherland, 加藤徳雄, 清水伸一, 鬼丸力也, 青山英史, 白土博樹
  日本放射線腫よう学会誌, 20, Supplement 1, 251, 2008年09月22日
  日本語
• 日常の臨床応用のためのLG‐DRRによる患者セットアップ検証
  KENNETH Sutherland, 石川正純, GERARD Bengua, 鬼丸力也, 清水伸一, 青山英史, 藤田勝久, 山崎里依, 白土博樹
  日本放射線腫よう学会誌, 20, Supplement 1, 264, 2008年09月22日
  日本語
• 分子イメージングを利用した患者位置確認のための対向型Open‐PET装置の製作と基礎検討
  棚邊哲史, 石川正純, 山口哲, 武島嗣英, GERARD Bengua, KENNETH Sutherland, 加藤徳雄, 清水伸一, 鬼丸力也, 白土博樹
  日本放射線腫よう学会誌, 20, Supplement 1, 268, 2008年09月22日
  日本語
• RTRT-based evaluation of the effectiveness of the stereotactic body frame in reducing intrafraction organ motion
  Bengua G, Ishikawa M, Sutherland K, Horita K, Yamazaki R, Fujita K, Onimaru R, Shimizu S, Shirato
  International Journal of Radiation Oncology Biology Physics, 72, 1, S610, S611, 2008年, ［査読有り］
• A simple parallelization of GEANT4 on a PC cluster with static scheduling for dose calculations
  K. Sutherland, S. Miyajima, H. Date
  FIRST EUROPEAN WORKSHOP ON MONTE CARLO TREATMENT PLANNING, 74, 012020, 2007年, ［査読有り］
  英語, 研究論文（国際会議プロシーディングス）

  
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