研究者詳細 - 岡本　昌士

論文 - 岡本　昌士

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Development and Validation of Transformer- and Convolutional Neural Network-Based Deep Learning Models to Predict Curve Progression in Adolescent Idiopathic Scoliosis 査読

Shinji Takahashi, Shota Ichikawa, Kei Watanabe, Haruki Ueda, Hideyuki Arima, Yu Yamato, Takumi Takeuchi, Naobumi Hosogane, Masashi Okamoto, Manami Umezu, Hiroki Oba, Yohan Kondo, Shoji Seki

Journal of Clinical Medicine 14 ( 20 ) 7216 - 7216 2025年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：MDPI AG

Background/Objectives: The clinical management of adolescent idiopathic scoliosis (AIS) is hindered by the inability to accurately predict curve progression. Although skeletal maturity and the initial Cobb angle are established predictors of progression, their combined predictive accuracy remains limited. This study aimed to develop a robust and interpretable artificial intelligence (AI) system using deep learning (DL) models to predict the progression of scoliosis using only standing frontal radiographs. Methods: We conducted a multicenter study involving 542 patients with AIS. After excluding 52 borderline progression cases (6–9° progression in the Cobb angle), 294 and 196 patients were assigned to progression (≥10° increase) and non-progression (≤5° increase) groups, respectively, considering a 2-year follow-up. Frontal whole spinal radiographs were preprocessed using histogram equalization and divided into two regions of interest (ROIs) (ROI 1, skull base–femoral head; ROI 2, C7–iliac crest). Six pretrained DL models, including convolutional neural networks (CNNs) and transformer-based models, were trained on the radiograph images. Gradient-weighted class activation mapping (Grad-CAM) was further performed for model interpretation. Results: Ensemble models outperformed individual ones, with the average ensemble model achieving area under the curve (AUC) values of 0.769 for ROI 1 and 0.755 for ROI 2. Grad-CAM revealed that the CNNs tended to focus on the local curve apex, whereas the transformer-based models demonstrated global attention across the spine, ribs, and pelvis. Models trained on ROI 2 performed comparably with respect to those using ROI 1, supporting the feasibility of image standardization without a loss of accuracy. Conclusions: This study establishes the clinical potential of transformer-based DL models for predicting the progression of scoliosis using only plain radiographs. Our multicenter approach, high AUC values, and interpretable architectures support the integration of AI into clinical decision-making for the early treatment of AIS.

DOI： 10.3390/jcm14207216

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主観型画像解析システムのための実空間内に存在する医療画像を対象とした物体検出モデルの開発；初期検討査読

梅室愛華, 佐藤充, 小倉敏裕, 近藤世範, 岡本昌士

医用画像情報学会雑誌 42 ( 4 ) 2025年9月

Radiomic Fingerprints: Automated Personal Identification in Mass Disasters Using Shape-Based Features of Thoracic Vertebral Bodies on CT 査読

Shota Ichikawa, Yohan Kondo, Masashi Okamoto, Tatsuya Kondo, Naoya Takahashi

Journal of Imaging Informatics in Medicine 2025年6月

深層学習を用いた領域抽出および脊椎パラメータ計測自動化の検討

木俣太一, 岡本昌士, 小林桜子, 近藤達也, 市川翔太, 佐藤充, 近藤世範

医用画像情報学会雑誌 42 ( 1 ) xli - xlii 2025年3月

Development of a Patient-Radiopharmaceutical Matching Verification System for Preventing Misadministration of Radioactive Drugs Using Mixed Reality ―Development of a deep-learning model based on video acquired by a camera mounted on a mixed reality device― 査読

Mitsuru SATO, Hiromitsu HOSHINO, Masataka SHIMIZU, Hiromitsu DAISAKI, Toshihiro OGURA, Shota ICHIKAWA, Tatsuya KONDO, Masashi OKAMOTO

RADIOISOTOPES 74 ( 1 ) 25 - 37 2025年3月

Pilot Study on Using Large Language Models for Educational Resource Development in Japanese Radiological Technologist Exams 査読

Tatsuya Kondo, Masashi Okamoto, Yohan Kondo

Medical Science Educator 2025年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Springer Science and Business Media LLC

Abstract

In this study, we explored the potential application of large language models (LLMs) to the development of educational resources for medical licensure exams in non-English-speaking contexts, focusing on the Japanese Radiological Technologist National Exam. We categorized multiple-choice questions into image-based, calculation, and textual types. We generated explanatory texts using Copilot, an LLM integrated with Microsoft Bing, and assessed their quality on a 0–4-point scale. LLMs achieved high performance for textual questions, which demonstrated their strong capability to process specialized content. However, we identified challenges in generating accurate formulas and performing calculations for calculation questions, as well as in interpreting complex medical images in image-based questions. To address these issues, we suggest using LLMs with programming functionalities for calculations and using keyword-based prompts for medical image interpretation. The findings highlight the active role of educators in managing LLM-supported learning environments, particularly by validating outputs and providing supplementary guidance to ensure accuracy. Furthermore, the rapid evolution of LLM technology necessitates continuous adaptation of utilization strategies to align with their advancing capabilities. In this study, we underscored the potential of LLMs to enhance educational practices in non-English-speaking regions, while addressing critical challenges to improve their reliability and utility.

DOI： 10.1007/s40670-024-02251-1

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その他リンク： https://link.springer.com/article/10.1007/s40670-024-02251-1/fulltext.html

A noncontact operating system using motion sensors for image display to avoid communication errors in gastrointestinal fluoroscopy 査読

Mitsuru SATO, Zen HAYAMA, Chihiro TSUCHIDA, Yohan KONDO, Masashi OKAMOTO, Toshihiro OGURA, Hiromitsu DAISAKI

The Japanese Journal of Ergonomics 2024年12月

Automated Prediction of Thoracic Vertebral Body Diameters from Computed Tomography Scans Using Deep Learning 査読

Shota Ichikawa, Yohan Kondo, Masashi Okamoto, Tatsuya Kondo, Naoya Takahashi

Journal of Health Sciences of Niigata University 21 2024年10月

低線量画像診断装置(EOSイメージングシステム)を用いた骨密度・筋肉量推定の精度検証

末原和樹, 谷懿, 大竹義人, 上村圭亮, 岡本昌士, 徳永邦彦, 政木勇人, 崇風まあぜん, 佐藤嘉伸

日本コンピュータ外科学会誌 26 ( 2 ) 208 - 208 2024年10月

Assessment of spinal alignment in standing position using Biplanar X-ray images and three-dimensional vertebral models 査読

Koichi Kobayashi, Makoto Sakamoto, Keisuke Sasagawa, Masaaki Nakai, Masashi Okamoto, Kazuhiro Hasegawa, Kengo Narita

Porto Biomedical Journal 9 ( 3 ) 2024年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Ovid Technologies (Wolters Kluwer Health)

Abstract

We developed two methods for three-dimensional (3D) evaluation of spinal alignment in standing position by image matching between biplanar x-ray images and 3D vertebral models. One used a Slot-Scanning 3D x-ray Imager (sterEOS) to obtain biplanar x-ray images, and the other used a conventional x-ray system and a rotating table. The 3D vertebral model was constructed from the CT scan data. The spatial position of the vertebral model was determined by minimizing the contour difference between the projected image of the model and the biplanar x-ray images. Verification experiments were conducted using a torso phantom. The relative positions of the upper vertebrae to the lowest vertebrae of the cervical, thoracic, and lumbar vertebrae were evaluated. The mean, standard deviation, and mean square error of the relative position were less than 1° and 1 mm in all cases for sterEOS. The maximum mean squared errors of the conventional x-ray system and the rotating table were 0.7° and 0.4 mm for the cervical spine, 1.0° and 1.2 mm for the thoracic spine, and 1.1° and 1.2 mm for the lumbar spine. Therefore, both methods could be useful for evaluating the spinal alignment in standing position.

DOI： 10.1097/j.pbj.0000000000000256

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Contactless operation system development for radiographic consoles using a motion controller to prevent unknown viruses: proof of concept 査読

Mitsuru Sato, Chihiro Tsuchida, Zen Hayama, Yohan Kondo, Masashi Okamoto, Toshihiro Ogura, Hiromitsu Daisaki

Medical Imaging and Information Sciences 41 ( 1 ) 15 - 21 2024年3月

Development of a Patient–Radiopharmaceutical Matching System Using Smartphone to Prevent Misadministration: Feasibility Study 査読

Mitsuru Sato, Hiromitsu Hoshino, Masataka Shimizu, Hiromitsu Daisaki, Shota Ichikawa, Tatsuya Kondo, Masashi Okamoto

RADIOISOTOPES 73 ( 1 ) 69 - 80 2024年3月

Racial differences in whole‑body sagittal alignment between Asians and Caucasians based on international multicenter data 査読

Jun Ouchida, Hiroaki Nakashima, Tokumi Kanemura, Masashi Okamoto, Shun Hatsushikano, Shiro Imagama, Jean Charles Le Huec, Kazuhiro Hasegawa

European Spine Journal 32 ( 10 ) 3608 - 3615 2023年6月

Improvement of teaching materials for anatomy by use of virtual reality system 査読

Mitsuru Sato, Naoya Takahashi, Masashi Okamoto

The Japan Association of Radiological Technologists 13 2023年3月

Deep learning-based classification of adequate sonographic images for self-diagnosing deep vein thrombosis 査読

Yusuke Nakayama, Mitsuru Sato, Masashi Okamoto, Yohan Kondo, Manami Tamura, Yasuko Minagawa, Mieko Uchiyama, Yosuke Horii

PLOS ONE 18 ( 3 ) e0282747 - e0282747 2023年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Public Library of Science (PLoS)

Background

Pulmonary thromboembolism is a serious disease that often occurs in disaster victims evacuated to shelters. Deep vein thrombosis is the most common reason for pulmonary thromboembolism, and early prevention is important. Medical technicians often perform ultrasonography as part of mobile medical screenings of disaster victims but reaching all isolated and scattered shelters is difficult. Therefore, deep vein thrombosis medical screening methods that can be easily performed by anyone are needed. The purpose of this study was to develop a method to automatically identify cross-sectional images suitable for deep vein thrombosis diagnosis so disaster victims can self-assess their risk of deep vein thrombosis.

Methods

Ultrasonographic images of the popliteal vein were acquired in 20 subjects using stationary and portable ultrasound diagnostic equipment. Images were obtained by frame split from video. Images were classified as “Satisfactory,” “Moderately satisfactory,” and “Unsatisfactory” according to the level of popliteal vein visualization. Fine-tuning and classification were performed using ResNet101, a deep learning model.

Results

Acquiring images with portable ultrasound diagnostic equipment resulted in a classification accuracy of 0.76 and an area under the receiver operating characteristic curve of 0.89. Acquiring images with stationary ultrasound diagnostic equipment resulted in a classification accuracy of 0.73 and an area under the receiver operating characteristic curve of 0.88.

Conclusion

A method for automatically identifying appropriate diagnostic cross-sectional ultrasonographic images of the popliteal vein was developed. This elemental technology is sufficiently accurate to automatically self-assess the risk of deep vein thrombosis by disaster victims.

DOI： 10.1371/journal.pone.0282747

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The age-specific normative values of standing whole-body sagittal alignment parameters in healthy adults: based on international multicenter data 査読

Jun Ouchida, Hiroaki Nakashima, Tokumi Kanemura, Masashi Okamoto, Shun Hatsushikano, Shiro Imagama, Jean Charles Le Huec, Kazuhiro Hasegawa

European Spine Journal 2022年11月

Development of individual identification method using thoracic vertebral features as biometric fingerprints 査読国際誌

Mitsuru Sato, Yohan Kondo, Masashi Okamoto, Naoya Takahashi

Scientific Reports 12 ( 1 ) 16274 - 16274 2022年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Springer Science and Business Media LLC

Abstract

Identification of individuals is performed when a corpse is found after a natural disaster, incident, or accident. DNA and dental records are frequently used as biometric fingerprints; however, identification may be difficult in some cases due to decomposition or damage to the corpse. The present study aimed to develop an individual identification method using thoracic vertebral features as a biological fingerprint. In this method, the shortest diameter in height, width, and depth of the thoracic vertebrae in the postmortem image and a control antemortem were recorded and a database was compiled using this information. The Euclidean distance or the modified Hausdorff distance was calculated as the distance between two points on the three-dimensional feature space of these measurement data. The thoracic vertebrae T1-12 were measured and the pair with the smallest distance was considered to be from the same person. The accuracy of this method for identifying individuals was evaluated by matching images of 82 cases from a total of 702 antemortem images and showed a hit ratio of 100%. Therefore, this method may be used to identify individuals with high accuracy.

DOI： 10.1038/s41598-022-20748-w

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その他リンク： https://www.nature.com/articles/s41598-022-20748-w

Development of a computer‑aided quality assurance support system for identifying hand X‑ray image direction using deep convolutional neural network 査読

Mitsuru Sato, Yohan Kondo, Masashi Okamoto

Radiological Physics and Technology 2022年8月

Development of a contactless operation system for radiographic consoles using an eye tracker for severe acute respiratory syndrome coronavirus 2 infection control: a feasibility study 査読

Mitsuru Sato, Mizuki Narita, Naoya Takahashi, Yohan Kondo, Masashi Okamoto, Toshihiro Ogura

ACTA IMEKO 11 ( 2 ) 1 - 8 2022年6月

Implications of the uncertainty of postoperative functional parameters for the preoperative planning of total hip arthroplasty 査読

Maximilian C. M. Fischer, Kunihiko Tokunaga, Masashi Okamoto, Juliana Habor, Klaus Radermacher

Journal of Orthopaedic Research 2022年3月

Slot scanning 3D X-ray imagerを用いた立位脊柱骨盤アライメント評価に関する研究

岡本昌士

新潟大学(新大院博（保）) 2022年3月

The anterior center edge angle has limited ability to predict three-dimensional coverage of the femoral head in patients with developmental dysplasia of the hip undergoing curved periacetabular osteotomy 査読国際誌

Keisuke Uemura, Toshihito Hiraiwa, Masashi Okamoto, Kunihiko Tokunaga, Andrew E. Anderson

Archives of Orthopaedic and Trauma Surgery 143 ( 3 ) 1323 - 1330 2022年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Springer Science and Business Media LLC

INTRODUCTION: Femoral head coverage in patients with hip dysplasia (DDH) is typically quantified using 2D measurements of the lateral center edge angle (LCEA) and anterior center edge angle (ACEA). However, as the morphology of DDH is complex and varies between patients, 2D measurements may not predict the true 3D femoral head coverage. Herein, 2D and 3D coverage were quantified before and after curved periacetabular osteotomy (CPO) and their relationships were assessed. MATERIALS AND METHODS: Forty-three hips that underwent CPO for DDH were analyzed. For 2D evaluation, LCEA was quantified from X-rays and CT images. The ACEA was measured from CT images (CT-ACEA) and digitally reconstructed radiographs generated from CT images (DRR-ACEA). Three-dimensional coverage was quantified from CT reconstructions of the hip and evaluated in the anterior, superior, posterior, and inferior regions of the femoral head. Two-dimensional measurements were correlated to 3D coverage to assess their relationships. RESULTS: The median preoperative 3D percent coverage was 17.7, 36.1, 56.1, and 14.6% for the anterior, superior, posterior, and inferior region, respectively. After CPO, all LCEAs and ACEAs increased significantly (all p < 0.001). For the 3D coverage, anterior and superior coverage significantly increased while the posterior and inferior coverage decreased (all p < 0.001). Moderate to strong correlations were detected between the two LCEAs and the 3D superior coverage in both the preoperative and postoperative period. For the correlation between 3D anterior coverage, no significant correlation was found between the CT-ACEA while a moderate correlation was found between the DRR-ACEA (rs = 0.41, p = 0.023). CONCLUSIONS: Our results indicate that the LCEA can be used to predict 3D coverage in the superior region of the femoral head. However, as the CT-ACEA or DRR-ACEA had no or only moderate correlation between the 3D anterior coverage, these measurements are not recommended for evaluating/estimating the 3D anterior coverage in patients with DDH.

DOI： 10.1007/s00402-021-04258-4

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その他リンク： https://link.springer.com/article/10.1007/s00402-021-04258-4/fulltext.html

The Patient-Specific Combined Target Zone for Morpho-Functional Planning of Total Hip Arthroplasty 査読

Juliana Habor, Maximilian Fischer, Kunihiko Tokunaga, Masashi Okamoto, Klaus Radermacher

Journal of Personalized Medicine 11 ( 8 ) 817 - 817 2021年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：MDPI AG

Background Relevant criteria for total hip arthroplasty (THA) planning have been introduced in the literature which include the hip range of motion, bony coverage, anterior cup overhang, leg length discrepancy, edge loading risk, and wear. The optimal implant design and alignment depends on the patient’s anatomy and patient-specific functional parameters such as the pelvic tilt. The approaches proposed in literature often consider one or more criteria for THA planning. but to the best of our knowledge none of them follow an integrated approach including all criteria for the definition of a patient-specific combined target zone (PSCTZ). Questions/purposes (1) How can we calculate suitable THA implant and implantation parameters for a specific patient considering all relevant criteria? (2) Are the resulting target zones in the range of conventional safe zones? (3) Do patients who fulfil these combined criteria have a better outcome score? Methods A method is presented that calculates individual target zones based on the morphology, range of motion and load acting on the hip joint and merges them into the PSCTZ. In a retrospective analysis of 198 THA patients, it was calculated whether the patients were inside or outside the Lewinnek safe zone, Dorr combined anteversion range and PSCTZ. The postoperative Harris Hip Scores (HHS) between insiders and outsiders were compared. Results 11 patients were inside the PSCTZ. Patients inside and outside the PSCTZ showed no significant difference in the HHS. However, a significant higher HHS was observed for the insiders of two of the three sub-target zones incorporated in the PSCTZ. By combining the sub-target zones in the PSCTZ, all PSCTZ insiders except one had an HHS higher than 90. Conclusions The results might suggest that, for a prosthesis implanted in the PSCTZ a low outcome score of the patient is less likely than using the conventional safe zones by Lewinnek and Dorr. For future studies, a larger cohort of patients inside the PSCTZ is needed which can only be achieved if the cases are planned prospectively with the method introduced in this paper. Clinical Relevance The method presented in this paper could help the surgeon combining multiple different criteria during THA planning and find the suitable implant design and alignment for a specific patient.

DOI： 10.3390/jpm11080817

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Influence of lumbosacral transitional vertebrae on spinopelvic parameters using biplanar slot scanning full body stereoradiography―analysis of 291 healthy volunteers 査読

Masashi Okamoto, Kazuhiro Hasegawa, Shun Hatsushikano, Koichi Kobayashi, Makoto Sakamoto, Masayuki Ohashi, Kei Watanabe

Journal of Orthopaedic Science 2021年5月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Elsevier BV

BACKGROUND: Proper identification of lumbosacral transitional vertebrae (LSTV) is important to characterize the relationship between the transitional segment and adjacent levels. Classical classification schemes are inaccurate with respect to the whole spine. We propose a precise vertebral numbering method and investigated the relationship between LSTV and whole-body sagittal alignment. METHODS: A total of 291 healthy adult volunteers with no history of spinal disease were evaluated with biplanar slot scanning full body stereoradiography to determine the prevalence of LSTV. Vertebrae were counted from the first cervical vertebra using both coronal and sagittal plane images. We then investigated the influence of LSTV on whole-body sagittal alignment in 279 participants. Whole-body key parameters descriptive statistics were compared among groups according to the number of vertebrae (L4, L5, and L6). Statistical analysis was performed between normal and LSTV cases using the Steel-Dwass analysis. RESULTS: Of the 291 subjects, 14 (4.8%) had 23 vertebrae and 16 (5.5%) had 25 vertebrae. Eleven (3.8%) had Th11, 3 (1.0%) had L4, and 1 (0.3%) had Th11 + L6, 16 (5.5%) had L6. Compared with the normal group, the sacral base in relation to the pelvis was higher in the L4 group and lower in the L6 group. The C2-C7 angle and lumbar lordosis (LL) were increased in both the L4 and L6 groups. All remaining parameters were decreased in the L4 group and increased in the L6 group. The relationship between LL and PI was similar in the normal and LSTV groups, despite the difference in the sacral base location. CONCLUSIONS: We propose a precise method for numbering the vertebrae using coronal and sagittal full body images. The spinopelvic parameters of the LSTV population significantly differed from those in the normal spine population due to differences in the sacral base location.

DOI： 10.1016/j.jos.2021.03.009

PubMed

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Sacral incidence to pubis: a novel and alternative morphologic radiological parameter to pelvic incidence in assessing spinopelvic sagittal alignment 査読

Yasuhito Takahashi, Kei Watanabe, Masashi Okamoto, Shun Hatsushikano, Kazuhiro Hasegawa, Naoto Endo

BMC Musculoskeletal Disorders 22 ( 1 ) 2021年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Springer Science and Business Media LLC

<title>Abstract</title><sec>
<title>Background</title>
Although pelvic incidence (PI) is a key morphologic parameter in assessing spinopelvic sagittal alignment, accurate measurements of PI become difficult in patients with severe hip dislocation or femoral head deformities. This study aimed to investigate the reliability of our novel morphologic parameters and the correlations with established sagittal spinopelvic parameters.

</sec><sec>
<title>Methods</title>
One hundred healthy volunteers (25 male and 75 female), with an average age of 38.9 years, were analysed. Whole-body alignment in the standing position was measured using a slot-scanning X-ray imager. We measured the established spinopelvic sagittal parameters and a novel parameter: the sacral incidence to pubis (SIP). The correlation coefficient of each parameter, regression equation of PI using SIP, and regression equation of lumbar lordosis (LL) using PI or SIP were obtained. The intraclass correlation coefficient (ICC) was calculated as an evaluation of the measurement reliability.

</sec><sec>
<title>Results</title>
Reliability analysis showed high intra- and inter-rater agreements in all the spinopelvic parameters, with ICCs > 0.9. The SIP and pelvic inclination angle (PIA) demonstrated strong correlation with PI (<italic>R</italic> = 0.96) and pelvic tilt (PT) (<italic>R</italic> = 0.92). PI could be predicted according to the regression equation: PI = − 9.92 + 0.905 * SIP (<italic>R</italic> = 0.9596, <italic>p</italic> < 0.0001). The ideal LL could be predicted using the following equation using PI and age: ideal LL = 32.33 + 0.623 * PI – 0.280 * age (<italic>R</italic> = 0.6033, <italic>p</italic> < 0.001) and using SIP and age: ideal LL = 24.29 + 0.609 * SIP – 0.309 * age (<italic>R</italic> = 0.6177, <italic>p</italic> < 0.001).

</sec><sec>
<title>Conclusions</title>
Both SIP and PIA were reliable parameters for determining the morphology and orientation of the pelvis, respectively. Ideal LL was accurately predicted using the SIP with equal accuracy as the PI. Our findings will assist clinicians in the assessment of spinopelvic sagittal alignment.

</sec><sec>
<title>Trial registration</title>
This study was retrospectively registered with the UMIN Clinical Trials Registry (<ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000049060">UMIN000042979</ext-link>; January 13, 2021).

</sec>

DOI： 10.1186/s12891-021-04093-z

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その他リンク： http://link.springer.com/article/10.1186/s12891-021-04093-z/fulltext.html

Preoperative factors improving the prediction of the postoperative sagittal orientation of the pelvis in standing position after total hip arthroplasty 査読

Maximilian C. M. Fischer, Kunihiko Tokunaga, Masashi Okamoto, Juliana Habor, Klaus Radermacher

Scientific Reports 10 ( 1 ) 2020年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Springer Science and Business Media LLC

<title>Abstract</title>
The aims of this study were to investigate if the sagittal orientation of the pelvis (SOP) in the standing position changes after total hip arthroplasty (THA) and evaluate what preoperative factors may improve the prediction of the postoperative standing SOP in the context of a patient-specific functional cup orientation. 196 primary THA patients from Japan were retrospectively selected for this study. Computed tomography imaging of the pelvis, EOS imaging of the lower body and lateral radiographs of the lumbar spine in the standing position were taken preoperatively. Common biometrics and preoperative Harris Hip Score were recorded. The EOS imaging in the standing position was repeated three months following THA. A 3D/2.5D registration process was used to determine the standing SOP. Thirty-three preoperative biometric, morphological and functional parameters were measured. Important preoperative parameters were identified that significantly improve the prediction of the postoperative standing SOP by using multiple linear LASSO regression. On average, the SOP changed significantly (<italic>p</italic> < 0.001) between the preoperative and postoperative standing position three months after THA by 3° ± 4° in the posterior direction. The age, standing lumbar lordosis angle (LLA) and preoperative supine and standing SOP significantly (<italic>p</italic> < 0.001) improve the prediction of the postoperative standing SOP. The linear regression model for the prediction of the postoperative standing SOP is significantly (<italic>p</italic> < 0.001) improved by adding the parameters preoperative standing SOP and LLA, in addition to the preoperative supine SOP, reducing the root mean square error derived from a leave-one-out cross-validation by more than 1°. The mean standing SOP in Japanese patients changes already three months after THA in comparison to the preoperative value. The preoperative factors age, LLA, supine and standing SOP can significantly improve the prediction of the postoperative standing SOP and should be considered within the preoperative planning process of a patient-specific functional cup orientation.

DOI： 10.1038/s41598-020-72782-1

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その他リンク： http://www.nature.com/articles/s41598-020-72782-1

Correction surgery for adult spinal deformity improves not only spinopelvic alignment but also the three-dimensional alignment of the lower extremities 査読

Yusuke Sato, Kazuhiro Hasegawa, Masashi Okamoto, Shun Hatsushikano, Yoshinori Ishii, Kei Watanabe, Yasushi Oshima, Haruka Shimoda, Takao Homma

Journal of Orthopaedic Science 25 ( 6 ) 946 - 952 2020年11月

Bayesian U-netを用いた股関節形成不全症例の筋萎縮の評価

上村圭亮, 大竹義人, 岡本昌士, 徳永邦彦, 高尾正樹, 菅野伸彦, 佐藤嘉伸

日本コンピュータ外科学会誌 22 ( 4 ) 298 - 299 2020年11月

Compensation for standing posture by whole-body sagittal alignment in relation to health-related quality of life 査読国際誌

Kazuhiro Hasegawa, Masashi Okamoto, Shun Hatsushikano, Kei Watanabe, Masayuki Ohashi, Jean-Marc Vital, Jean Dubousset

The Bone & Joint Journal 102-B ( 10 ) 1359 - 1367 2020年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：British Editorial Society of Bone & Joint Surgery

<sec><title>Aims</title> The aim of this study is to test the hypothesis that three grades of sagittal compensation for standing posture (normal, compensated, and decompensated) correlate with health-related quality of life measurements (HRQOL).

</sec><sec><title>Methods</title> A total of 50 healthy volunteers (normal), 100 patients with single-level lumbar degenerative spondylolisthesis (LDS), and 70 patients with adult to elderly spinal deformity (deformity) were enrolled. Following collection of demographic data and HRQOL measured by the Scoliosis Research Society-22r (SRS-22r), radiological measurement by the biplanar slot-scanning full body stereoradiography (EOS) system was performed simultaneously with force-plate measurements to obtain whole body sagittal alignment parameters. These parameters included the offset between the centre of the acoustic meatus and the gravity line (CAM-GL), saggital vertical axis (SVA), T1 pelvic angle (TPA), McGregor slope, C2-7 lordosis, thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), PI-LL, sacral slope (SS), pelvic tilt (PT), and knee flexion. Whole spine MRI examination was also performed. Cluster analysis of the SRS-22r scores in the pooled data was performed to classify the subjects into three groups according to the HRQOL, and alignment parameters were then compared among the three cluster groups.

</sec><sec><title>Results</title> On the basis of cluster analysis of the SRS-22r subscores, the pooled subjects were divided into three HRQOL groups as follows: almost normal (mean 4.24 (SD 0.32)), mildly disabled (mean 3.32 (SD 0.24)), and severely disabled (mean 2.31 (SD 0.35)). Except for CAM-GL, all the alignment parameters differed significantly among the cluster groups. The threshold values of key alignment parameters for severe disability were TPA > 30°, C2-7 lordosis > 13°, PI-LL > 30°, PT > 28°, and knee flexion > 8°. Lumbar spinal stenosis was found to be associated with the symptom severity.

</sec><sec><title>Conclusion</title> This study provides evidence that the three grades of sagittal compensation in whole body alignment correlate with HRQOL scores. The compensation grades depend on the clinical diagnosis, whole body sagittal alignment, and lumbar spinal stenosis. The threshold values of key alignment parameters may be an indication for treatment. Cite this article: Bone Joint J 2020;102-B(10):1359–1367.

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DOI： 10.1302/0301-620x.102b10.bjj-2019-1581.r2

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Etiology and clinical manifestations of double-level versus single-level lumbar degenerative spondylolisthesis 査読

Kazuhiro Hasegawa, Masashi Okamoto, Shun Hatsushikano, Haruka Shimoda, Yusuke Sato, Kei Watanabe

Journal of Orthopaedic Science 25 ( 5 ) 812 - 819 2020年9月

立位姿勢維持機構と健康関連QOL 全身骨アライメント・バランス・筋量の関与

長谷川和宏, 岡本昌士, 初鹿野駿, 下田晴華, 本間隆夫, 渡辺慶, 大橋正幸

日本整形外科学会雑誌 94 ( 8 ) S1778 - S1778 2020年9月

Can measurements from an anteroposterior radiograph predict pelvic sagittal inclination? 査読国際誌

Keisuke Uemura, Penny R. Atkins, Masashi Okamoto, Kunihiko Tokunaga, Andrew E. Anderson

Journal of Orthopaedic Research 38 ( 7 ) 1477 - 1485 2020年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Wiley

Pelvic sagittal inclination (PSI) is often evaluated in patients with hip pathology using lateral radiographs. However, it would be useful if PSI could be predicted from an anteroposterior radiograph since this film is ubiquitous in the evaluation of hip pathology. Herein, computer-modeling was applied to predict PSI from radiographic measurements assessed in the anteroposterior plane. Three-dimensional surface models of the pelvis, femur, and sacrum were reconstructed from computed tomography images of 50 women with hip dysplasia. This study cohort was selected as changes in PSI alter femoral head coverage, which is relevant to the diagnosis and treatment of hip dysplasia, a known cause of hip osteoarthritis. Five radiographic parameters commonly used to independently estimate PSI were evaluated after bone surfaces were projected to an anteroposterior plane, including the symphysis to sacrococcygeal joint distance (S-S distance), the pelvic foramen aspect ratio (PF ratio), the distance between the symphysis and a line connecting the femoral head centers (S-H distance), the sacro-femoral-pubic angle (SFP angle), and the pelvic vertical ratio (PVR). Regression models determined the ability of these parameters to predict PSI from -20° to 20° at 1° increment. All five parameters showed a strong correlation with the PSI (all r > 0.9). From the regression models, PSI was estimated with a median (maximum) absolute error of 3.6° (18.4°), 3.8° (17.7°), 5.2° (17.9°), 5.8° (28.8°), and 3.2° (23.5°) for the S-S distance, PF ratio, S-H distance, SFP angle, and PVR, respectively. The regression model for S-S distance had a mean slope of 2.18 that ranged from 1.98 to 2.41 when the sacrococcygeal joint was located superior to the symphysis. Results indicated that substantial errors occur when estimating the actual value of PSI from an anteroposterior radiograph. However, the change in PSI could be estimated from the S-S distance, which may aid surgeons to successfully increase head coverage through periacetabular osteotomy and to locate the acetabular cup in a functional position for total hip arthroplasty.

DOI： 10.1002/jor.24701

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その他リンク： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/jor.24701

Relative position of sacral base in the pelvis and its correlation with spino-pelvic parameters 査読

Masashi Okamoto, Kazuhiro Hasegawa, Shun Hatsushikano, Kei Watanabe, Haruka Shimoda, Koichi Kobayashi, Makoto Sakamoto

European Spine Journal 29 ( 3 ) 446 - 454 2020年3月

Curved periacetabular osteotomy術前後における骨頭の2D、3D被覆に関して

上村圭亮, 岡本昌士, 徳永邦彦, Anderson Andrew

日本CAOS研究会・日本最小侵襲整形外科学会プログラム・抄録集 14回・26回 172 - 172 2020年3月

Patient-specific ROM and load-based target zone for total hip arthroplasty and its application in a retrospective analysis 査読

Juliana Habor, Maximilian, C.M. Fischer, Kunihiko Tokunaga, Masashi Okamoto, Klaus Rademacher

EPiC Series in Health Science 3 161 - 165 2019年10月

腰椎変性疾患に対する除圧術および固定術前後の立位全身矢状面アライメントおよびバランスの変化査読

初鹿野駿, 長谷川和宏, 岡本昌士, 佐藤雄亮, 下田晴華

Journal of Spine Research 10 ( 9 ) 1362 - 1366 2019年9月

Lumbar lordosis does not correlate with pelvic incidence in the cases with the lordosis apex located at L3 or above 査読

Osamu Tono, Kazuhiro Hasegawa, Masashi Okamoto, Shun Hatsushikano, Haruka Shimoda, Kei Watanabe, Katsumi Harimaya

European Spine Journal 28 ( 9 ) 1948 - 1954 2019年9月

Proximal femoral asymmetry in Japanese patients before total hip arthroplasty. 査読

Maximilian, C.M. Fischer, Kunihiko Tokunaga, Masashi Okamoto, Klaus Rademacher

EPiC Series in Health Science 3 127 - 132 2019年6月

Difference in whole spinal alignment between supine and standing positions in patients with adult spinal deformity using a new comparison method with slot-scanning three-dimensional X-ray imager and computed tomography through digital reconstructed radiography 査読

Kazuhiro Hasegawa, Masashi Okamoto, Shun Hatsushikano, Gabriel Caseiro, Kei Watanabe

BMC Musculoskeletal Disorders 19 ( 1 ) 2018年12月

Sagittal balance measures are more reproducible when measured in 3D vs in 2D using full-body EOS® images 査読

Masashi Okamoto, Fouad Jabour, Kenichiro Sakai, Shun Hatsushikano, J. C. Le Huec, Kazuhiro Hasegawa

European Radiology 28 ( 11 ) 4570 - 4577 2018年11月

Relationship between sagittal radiographic parameters and disability in patients with spinal disease using 3D standing analysis 査読

Hiroyuki Yoshihara, Kazuhiro Hasegawa, Masashi Okamoto, Shun Hatsushikano, Kei Watanabe

Orthopaedics & Traumatology: Surgery & Research 104 ( 7 ) 1017 - 1023 2018年11月

Why did anterior dislocation occur during dandling her baby in front of her in standing position after THA? 査読

Kunihiko Tokunaga, Juliana Habor, Maximilian, C.M. Fischer, Masashi Okamoto, Klaus Rademacher

EPiC Series in Health Science 2 219 - 222 2018年7月

Slot scanning 3D X-ray imager (EOS) を用いた立位脊柱アライメントに関する研究査読

岡本昌士

新潟大学(新大院修（保）) ( 250 ) 2018年3月

成人脊柱変形に対する後方脊柱矯正固定術はアライメントと共に立位バランスも改善させる

下田晴華, 長谷川和宏, 岡本昌士, 初鹿野駿, 本間隆夫, 小野真稔, 大橋正幸, 渡辺慶, 平野徹

Journal of Spine Research 9 ( 3 ) 608 - 608 2018年3月

腰椎前彎の頂椎高位によって脊柱骨盤矢状面アライメントは有意に変化する

東野修, 長谷川和宏, 下田晴華, 岡本昌士, 初鹿野駿, 本間隆夫, 渡辺慶, 平野徹, 大橋正幸, 播广谷勝三

Journal of Spine Research 9 ( 3 ) 619 - 619 2018年3月

成人期以降の脊柱変形は立位によって胸腰椎後側彎および骨盤後傾が悪化する

長谷川和宏, 岡本昌士, 初鹿野駿, 下田晴華, 本間隆夫, 大橋正幸, 渡辺慶, 平野徹

Journal of Spine Research 9 ( 3 ) 455 - 455 2018年3月

成人期の脊柱変形の病態と治療体系成人期以降の脊柱変形における立位アライメントおよびバランス

長谷川和宏, 岡本昌士, 初鹿野駿, 下田晴華, 本間隆夫, 大橋正幸, 渡辺慶, 平野徹, 遠藤直人

日本整形外科学会雑誌 92 ( 2 ) S322 - S322 2018年3月

成人脊柱変形では立位で胸腰椎後側彎が悪化する Slot-scanning X-ray imager(立位)とCT(臥位)での比較

長谷川和宏, 岡本昌士, 初鹿野駿, 下田晴華, 本間隆夫, 渡辺慶, 大橋正幸, 平野徹, 遠藤直人

日本整形外科学会雑誌 92 ( 3 ) S680 - S680 2018年3月

EOS Revealed Correlation of the Anterior Pelvic Plane Angle with the Pelvic Alignment Parameters of Pre- and Post-Operative Patients in Supine and Standing Positions 査読

Kunihiko Tokunaga, Masashi Okamoto

Orthopaedic Proceedings 99 ( 20 ) 1 - 4 2018年2月