306 research outputs found
症候性・無症候性肩腱板断裂症例における肩関節筋力、筋断面積、肩峰骨頭間距離、棘上筋腱端部厚の比較
京都大学新制・課程博士博士(人間健康科学)甲第24541号人健博第112号新制||人健||8(附属図書館)京都大学大学院医学研究科人間健康科学系専攻(主査)教授 黒木 裕士, 教授 青山 朋樹, 教授 松田 秀一学位規則第4条第1項該当Doctor of Human Health SciencesKyoto UniversityDFA
Patient Re-Identification Based on Deep Metric Learning in Trunk Computed Tomography Images Acquired from Devices from Different Vendors
The version of record of this article, first published in Journal of Imaging Informatics in Medicine, is available online at Publisher’s website: https://doi.org/10.1007/s10278-024-01017-w.During radiologic interpretation, radiologists read patient identifiers from the metadata of medical images to recognize the patient being examined. However, it is challenging for radiologists to identify “incorrect” metadata and patient identification errors. We propose a method that uses a patient re-identification technique to link correct metadata to an image set of computed tomography images of a trunk with lost or wrongly assigned metadata. This method is based on a feature vector matching technique that uses a deep feature extractor to adapt to the cross-vendor domain contained in the scout computed tomography image dataset. To identify “incorrect” metadata, we calculated the highest similarity score between a follow-up image and a stored baseline image linked to the correct metadata. The re-identification performance tests whether the image with the highest similarity score belongs to the same patient, i.e., whether the metadata attached to the image are correct. The similarity scores between the follow-up and baseline images for the same “correct” patients were generally greater than those for “incorrect” patients. The proposed feature extractor was sufficiently robust to extract individual distinguishable features without additional training, even for unknown scout computed tomography images. Furthermore, the proposed augmentation technique further improved the re-identification performance of the subset for different vendors by incorporating changes in width magnification due to changes in patient table height during each examination. We believe that metadata checking using the proposed method would help detect the metadata with an “incorrect” patient identifier assigned due to unavoidable errors such as human error
Biological fingerprint using scout computed tomographic images for positive patient identification
Purpose: Management of patient identification is an important issue that should be addressed to ensure patient safety while using modern healthcare systems. Patient identification errors can be mainly attributed to human errors or system problems. An error-tolerant system, such as a biometric system, should be able to prevent or mitigate potential misidentification occurrences. Herein, we propose the use of scout computed tomography (CT) images for biometric patient identity verification and present the quantitative accuracy outcomes of using this technique in a clinical setting. Methods: Scout CT images acquired from routine examinations of the chest, abdomen, and pelvis were used as biological fingerprints. We evaluated the resemblance of the follow-up with the baseline image by comparing the estimates of the image characteristics using local feature extraction and matching algorithms. The verification performance was evaluated according to the receiver operating characteristic (ROC) curves, area under the ROC curves (AUC), and equal error rates (EER). The closed-set identification performance was evaluated according to the cumulative match characteristic curves and rank-one identification rates (R1). Results: A total of 619 (383 males, 236 females, age range 21–92 years) patients who underwent baseline and follow-up chest–abdomen–pelvis CT scans on the same CT system were analyzed for verification and closed-set identification. The highest performances of AUC, EER, and R1 were 0.998, 1.22%, and 99.7%, respectively, in the considered evaluation range. Furthermore, to determine whether the performance decreased in the presence of metal artifacts, the patients were classified into two groups, namely scout images with (255 patients) and without (364 patients) metal artifacts, and the significance test was performed for two ROC curves using the unpaired Delong's test. No significant differences were found between the ROC performances in the presence and absence of metal artifacts when using a sufficient number of local features. Our proposed technique demonstrated that the performance was comparable to that of conventional biometrics methods when using chest, abdomen, and pelvis scout CT images. Thus, this method has the potential to discover inadequate patient information using the available chest, abdomen, and pelvis scout CT image; moreover, it can be applied widely to routine adult CT scans where no significant body structure effects due to illness or aging are present. Conclusions: Our proposed method can obtain accurate patient information available at the point-of-care and help healthcare providers verify whether a patient’s identity is matched accurately. We believe the method to be a key solution for patient misidentification problems.This is the peer reviewed version of the following article: Ueda, Y., Morishita, J. and Hongyo, T. (2019), Biological fingerprint using scout computed tomographic images for positive patient identification. Med. Phys., 46: 4600-4609, which has been published in final form at https://doi.org/10.1002/mp.13779. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited
RELATIONSHIP BETWEEN ANTERIOR TIBIAL TRANSLATION AND ISOMETRIC STRENGTH IN FEMALE ATHLETES
The purpose of this study was to determine whether the isometric strength of the muscles around the knee and hip is associated with anterior tibial translation. Forty-four female high school basketball players participated in this study. Anterior tibial translation was measured with a Kneelax 3 arthrometer. The isometric strengths of knee flexion, knee extension, and hip abduction were determined with a hand-held dynamometer. In the case of both the legs, significant correlations were found between the anterior tibial translation, knee extension strength, and hamstring/quadriceps strength (H/Q) ratio. No significant correlations were found between the anterior tibial translation and the knee flexion and hip abduction strengths. Muscle imbalance between the quadriceps and hamstring muscles may lead to greater anterior tibial translation
Thermoluminescence studies of ordinary chondrites in the Japanese Antarctic meteorite collection, IV: Asuka ordinary chondrites
We measured TL properties of ninety Asuka (A) ordinary chondrites (LL: 16, L: 27, H: 47) from Japanese Antarctic meteorite collection. Most of the chondrites had TL sensitivities over 0.1, corresponding to petrologic subtype 3.5-3.9. Eight chondrites, A-881244 (L3), A-881607 (LL3), A-881328 (LL3), A-881408 (LL3), A-881397 (LL3), A-881522 (L3), A-881357 (LL3 or L3), and A-881199 (LL3) were revealed to be primitive ordinary chondrites under petrologic subtype 3.4, and therefore they are particularly significant in understanding the nature of primitive material in the solar system. Twenty-one chondrites with low TL sensitivities below 0.1 (Dhajala=1) had suffered remarkable shock and/or terrestrial weathering. Samples were mainly from three different dirt bands south of the Sr Rondane Mountains at D1, D2, and D3 sites. LT/HT distribution at D1 site suggested that chondrites at D1 site had shorter terrestrial ages than those at D2 and D3. A-880709, A-88710, A-88774, A-881324 which had extremely low LT/HT ratio under 0.1, and A-881484 and A-881546 which might be heated over 400°C were presumed to have small perihelia. We found 26 TL potential paired fragments, and 9 groups. A group of H3 at D1 site comprises a chain of paired fragments. A H3 chondrite might shower near the Asuka
平面ならびにねじれた構造を有する縮合多環芳香族化合物の合成と分子配向の制御
学位の種別:課程博士University of Tokyo(東京大学
Effect of different trunk postures on scapular muscle activities and kinematics during shoulder external rotation
[Background]Shoulder external rotation at abduction (ER) is a notable motion in overhead sports because it could cause strong stress to the elbow and shoulder joint. However, no study has comprehensively investigated the effect of different trunk postures during ER. This study aimed to investigate the effect of different trunk postures on scapular kinematics and muscle activities during ER. [Methods]Fourteen healthy men performed active shoulder external rotation at 90° of abduction with the dominant arm in 15 trunk postures. At maximum shoulder external rotation in 15 trunk postures, including 4 flexion-extension, 6 trunk rotation, and 4 trunk side-bending postures, as well as upright posture as a control, scapular muscle activities and kinematics were recorded using surface electromyography and an electromagnetic tracking device, respectively. The data obtained in the flexion-extension, trunk rotation, and trunk side-bending postures were compared with those obtained in the upright posture. [Results]In the flexion-extension condition, scapular posterior tilt and external rotation significantly decreased, but the muscle activities of the lower trapezius and infraspinatus significantly increased in maximum trunk flexion. Moreover, scapular upward rotation and the activity of the serratus anterior significantly increased in maximum trunk extension. In the rotation condition, scapular posterior tilt and external rotation significantly decreased, but the activity of the serratus anterior significantly increased in the maximum contralateral trunk rotation posture. In the trunk side-bending condition, scapular posterior tilt and the external rotation angle significantly decreased. [Conclusio]Trunk postures affected scapular kinematics and muscle activities during ER. Our results suggest that different trunk postures activate the lower trapezius and serratus anterior, which induce scapular posterior tilt
Compensation strategy of shoulder synergist muscles is not stereotypical in patients with rotator cuff repair
Rotator cuff tear is a common shoulder injury that causes shoulder dysfunction and pain. Although surgical repair is the primary treatment for rotator cuff tear, it is well recognized that impaired force exertion of muscles connecting to the involved tendon and subsequent complemental change in the force exertion of synergist muscles persist even after repair. This study aimed to identify the compensation strategy of shoulder abductors by examining how synergist muscles respond to supraspinatus (SSP) muscle force deficit in patients with rotator cuff repair. Muscle shear modulus, an index of muscle force, was assessed for SSP, infraspinatus, upper trapezius, and middle deltoid muscles in repaired and contralateral control shoulders of 15 patients with unilateral tendon repair of the SSP muscle using ultrasound shear wave elastography while the patients passively or actively held their arm in shoulder abduction. In the repaired shoulder, the shear modulus of the SSP muscle declined, whereas that of other synergist muscles did not differ relative to that of the control. To find the association between the affected SSP and each of the synergist muscles, a regression analysis was used to assess the shear moduli at the population level. However, no association was observed between them. At the individual level, there was a tendency of variation among patients with regard to a specific muscle whose shear modulus complementarily increased. These results suggest that the compensation strategy for SSP muscle force deficit varies among individuals, being nonstereotypical in patients with rotator cuff injury
Agreement in rotator cuff muscles measurement between ultrasonography and magnetic resonance imaging
[Background/objective] It is important to assess the atrophy of the rotator cuff to better understand shoulder function and pain. Previously, magnetic resonance imaging has been used for the evaluation of atrophy of rotator cuff muscles, which is time consuming. Therefore, a measurement tool requiring little time and easy accessibility is clinically desirable to be used frequently in rehabilitation. Recently, rotator cuff muscles have been evaluated using ultrasonography. However, little is known about the agreement of evaluation in rotator cuff muscles between magnetic resonance imaging and ultrasonography. The purpose of this study was to demonstrate the agreement between the muscle thickness measurements of supraspinatus, infraspinatus, and teres minor muscles by ultrasonography and the cross-sectional area measured by magnetic resonance imaging in the patient with rotator cuff tears. [Methods] A total of 47 patients with rotator cuff tears were enrolled. There were the 37 small tears, four medium tears, and six large tears, and the involved rotator cuff muscles were the supraspinatus in 37 shoulders, and the supraspinatus and infraspinatus in 10 shoulders. The measuring variables were muscle thickness and cross-sectional area of supraspinatus, infraspinatus, and teres minor muscles by using magnetic resonance imaging. Further, the muscle thickness of the rotator cuff were assessed using ultrasonography. A single regression model was used for demonstrating the agreement between the cross-sectional area measurement by magnetic resonance imaging and the muscle thickness measured using ultrasonography and magnetic resonance imaging of rotator cuff muscles. Additionally, the Bland-Altman plots between magnetic resonance imaging and ultrasonography was analyzed. [Results] The cross-sectional area were correlated with the muscle thickness measurement of rotator cuff muscles by magnetic resonance imaging, significantly (supraspinatus: r = 0.84, infraspinatus: ρ = 0.63, teres minor: ρ = 0.61, all p < 0.001). There were significant agreements between the cross-sectional area measured by magnetic resonance imaging and muscle thickness measured by ultrasonography (supraspinatus: r = 0.80, infraspinatus: ρ = 0.78, teres minor: ρ = 0.74, all p < 0.001). Bland-Altman plots revealed significant correlations between the average and the difference of the two measurements in supraspinatus (r = 0.36, p = 0.012), infraspinatus (r = 0.38, p < 0.001), and teres minor (r = 0.42, p < 0.001). These results clarified the proportional bias between MRI and US. [Conclusion] This study showed that, similar to magnetic resonance imaging, ultrasonography is a useful tool for assessing muscle atrophy of supraspinatus, infraspinatus, and teres minor muscles
Comparison of scapular upward rotation during arm elevation in the scapular plane in healthy volunteers and patients with rotator cuff tears pre- and post-surgery.
[Background] Function loss caused by rotator cuff tears alters the scapular orientation, however, few prior studies have reported on scapular movements after rotator cuff repair. The purpose was to determine the scapular orientations before and after rotator cuff repair. [Methods] We recruited 14 healthy controls, 10 small and six massive rotator cuff tear in patients. The scapular upward rotation during arm elevation was analyzed using fluoroscopic imaging. [Findings] Before surgery, both rotator cuff groups demonstrated greater scapular upward rotation compared to healthy controls. Two months postoperation, the analyses showed significant differences between the patients with small rotator cuff tears and healthy controls at arm elevations of 90°, and between patients with both rotator cuff tear groups and healthy controls at arm elevations of 120°. At five months post-operation, significant differences still existed between the healthy controls and both rotator cuff groups. In regard to the temporal effects in the patients with small rotator cuff tears, the scapular upward rotation decreased significantly over time (2–5 months postoperation) at arm elevations of 120°. We did not identify a main effect owing to time in the patients with massive rotator cuff tears. [Interpretation] In patients with small rotator cuff tears, scapular upward rotation was reduced over the period of 2–5 months postoperation, however, the patients with massive rotator cuff tears showed greater scapular upward rotation throughout the experimental period. The results suggested that the execution of the rehabilitation program should consider that the tear size could affect scapular motion
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