Papers - Yamada, Yoshitake

A novel anteroposterior axis of the tibia for total knee arthroplasty: An upright weight-bearing computed tomography analysis.

Ryo Sasaki, Yasuo Niki, Kazuya Kaneda, Yoshitake Yamada, Takeo Nagura, Masaya Nakamura, Masahiro Jinzaki

The Knee (Knee)  36   80 - 86 2022.05

Accepted,  ISSN  0968-0160

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BACKGROUND: The traditional anteroposterior (AP) axis (i.e., Akagi's line) has been widely used as the tibial component AP axis during total knee arthroplasty (TKA). However, this AP axis has been defined based on computed tomography (CT) in a non-weight-bearing supine position. In this study, AP axes of the tibial plateau from upright CT in weight-bearing and non-weight-bearing positions were determined and compared. METHODS: This study included 43 knees from 23 healthy volunteers. CT images were obtained in weight-bearing and non-weight-bearing standing positions using a 320-detector row upright CT scanner. The line perpendicular to surgical transepicondylar axis projected onto the tibia plateau was determined as the AP axis in upright weight-bearing and non-weight-bearing conditions. Angular differences between these two conditions were measured. RESULTS: The upright weight-bearing AP axis was positioned in a mean of 7.4 ± 4.3° of internal rotation relative to the traditional AP axis. Distance between the traditional and upright weight-bearing AP axis was 2.9 ± 1.6 mm at the edge of the tibial plateau. The upright non-weight-bearing AP axis was positioned in a mean of 3.5 ± 4.1° of internal rotation relative to the traditional AP axis. Mean angular difference between weight-bearing and non-weight-bearing conditions was 3.9 ± 4.1°. CONCLUSIONS: The upright weight-bearing AP axis was positioned in 7.4° of internal rotation relative to the traditional AP axis, showing one-seventh of the tibial tuberosity away from the medial border of the tibial tubercle, which represents a practical landmark for the tibial component AP axis during TKA.

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Three-dimensional shoulder kinematics: Upright four-dimensional computed tomography in comparison with an optical three-dimensional motion capture system.

Yuki Yoshida, Noboru Matsumura, Azusa Miyamoto, Satoshi Oki, Yoichi Yokoyama, Minoru Yamada, Yoshitake Yamada, Masaya Nakamura, Takeo Nagura, Masahiro Jinzaki

Journal of orthopaedic research : official publication of the Orthopaedic Research Society (Journal of Orthopaedic Research)  41 ( 1 ) 196 - 205 2022.04

Accepted,  ISSN  0736-0266

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Although shoulder kinematics have been analyzed by various methods, dynamic shoulder motion is difficult to track. This study aimed to validate the shoulder kinematic analysis using upright four-dimensional computed tomography (4DCT) and to compare the results with optical three-dimensional motion capture. During active elevation, bilateral shoulders of 10 healthy volunteers were tracked using 4DCT and motion capture. The scapulothoracic and glenohumeral rotations and the scapulohumeral rhythm (SHR) at each position were calculated, and the differences between 4DCT and motion capture were compared. During 10°-140° of humerothoracic elevation, the scapulothoracic joint showed upward rotation, internal rotation, and posterior tilting, and the glenohumeral joint showed elevation, external rotation, and anterior plane of elevation in both analyses. In scapulothoracic rotations, the mean differences between the two analyses were -2.6° in upward rotation, 13.9° in internal rotation, and 6.4° in posterior tilting, and became significant with humerothoracic elevation ≥110° in upward rotation, ≥50° in internal rotation, and ≥100° in posterior tilting. In glenohumeral rotations, the mean differences were 3.7° in elevation, 9.1° in internal rotation, and -8.8° in anterior plane of elevation, and became significant with humerothoracic elevation ≥110° in elevation, ≥90° in internal rotation, and ≥100° in anterior plane of elevation. The mean overall SHRs were 1.8 in 4DCT and 2.4 in motion capture, and the differences became significant with humerothoracic elevation ≥100°. The 4DCT analysis of in vivo shoulder kinematics using upright CT scanner is feasible, but the values were different from those by skin-based analysis at the elevated arm positions. This article is protected by copyright. All rights reserved.

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Three-dimensional alignment of the upper extremity in the standing neutral position in healthy subjects.

Yuki Yoshida, Noboru Matsumura, Yoshitake Yamada, Satoshi Hiraga, Kazunori Ishii, Satoshi Oki, Yoichi Yokoyama, Minoru Yamada, Masaya Nakamura, Takeo Nagura, Masahiro Jinzaki

Journal of orthopaedic surgery and research (Journal of Orthopaedic Surgery and Research)  17 ( 1 ) 239 - 239 2022.04

Accepted

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BACKGROUND: Though alignment of the spine and lower extremities in the standing neutral position has been evaluated, a few studies evaluating the alignment of the upper extremities have also been made. This study assessed the normal alignment of the upper extremities in the standing neutral position and clarified the three-dimensional angular rotations of the upper extremity joints. METHODS: Computed tomography (CT) images of 158 upper extremities from 79 healthy volunteers were prospectively acquired in the standing neutral position using an upright CT scanner. Three-dimensional coordinate systems of the thorax, scapula, humerus, and forearm were designated, and three-dimensional angular rotations of the scapulothoracic, glenohumeral, and elbow joints were calculated. RESULTS: The median angle of the scapulothoracic joint was 9.2° (interquartile range [IQR], 5.2°-12.5°) of upward rotation, 29.0° (IQR, 24.9°-33.3°) of internal rotation, and 7.9° (IQR, 4.3°-11.8°) of anterior tilt. The median angle of the glenohumeral joint was 4.5° (IQR, 0.9°-7.8°) of abduction, 9.0° (IQR, 2.2°-19.0°) of internal rotation, and 0.3° (IQR, - 2.6°-3.1°) of extension. The median angle of the elbow joint was 9.8° (IQR, 6.9°-12.4°) of valgus, 90.2° (IQR, 79.6°-99.4°) of pronation, and 15.5° (IQR, 13.2°-18.1°) of flexion. Correlations in angular rotation values were found between the right and left upper extremities and between joints. CONCLUSIONS: This study clarified the three-dimensional angular rotation of upper extremity joints in the standing neutral position using an upright CT scanner. Our results may provide important insights for the functional evaluation of upper extremity alignment.

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Knee varus alters three-dimensional ankle alignment in standing- a study with upright computed tomography.

Satoshi Hakukawa, Kazuya Kaneda, Satoshi Oki, Kengo Harato, Yoshitake Yamada, Yasuo Niki, Takeo Nagura, Masaya Nakamura, Masahiro Jinzaki

BMC musculoskeletal disorders (BMC Musculoskeletal Disorders)  23 ( 1 ) 321 - 321 2022.04

Accepted

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BACKGROUND: For knee osteoarthritis (OA) treatment, it is important to correct the lower limb alignment including the foot. However, in the upright position, lower limb alignment is generally assessed from the body surface or radiographs, and it is a challenge to capture the exact characteristics of three-dimensional lower limb alignment. The purpose of the study was to measure lower limb alignment in patients with knee OA using upright computed tomography (CT) and radiography, and to identify features of knee joint deformity. METHODS: A total of 45 limbs in 25 patients with knee OA were enrolled. The subjects underwent both upright CT and radiography for the whole lower limb in the standing position. The joint angles were calculated on both images. The degree of knee OA was classified according to Kellgren-Lawrence (KL) grade by referring to radiography, which is mainly based on the degree of articular cartilage loss and severity of osteophytes, and the characteristics or correlation between knee and ankle joint in each group was investigated. RESULTS: In KL-I, there was an association between varus of the knee joint and internal rotation of the talocrural joint (r = 0.76, P < 0.05). In KL-II, there was an association between varus of the knee joint and eversion of the subtalar joint (r = 0.63, P < 0.05) and talocrural joint (r = - 0.65, P < 0.05). In KL-III, there was an association between varus of the knee joint and internal rotation of the subtalar joint (r = - 0.62, P < 0.05), and in KL-IV, there was an association between varus of the knee joint and internal rotation of the subtalar joint (r = - 0.58, P < 0.05). CONCLUSIONS: The lower limb alignment of patients with knee OA in the standing position was found that as knee OA worsened, it became apparent that compensatory knee joint alignment depended on the ankle joint rather than the subtalar joint. The results may help in the rehabilitation of patients with knee OA, since the ankle joint alignment has a significant impact on the knee joint during coarse movements involving load.

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Increase in tibial internal rotation due to weight-bearing is a key feature to diagnose early-stage knee osteoarthritis: a study with upright computed tomography.

Kazuya Kaneda, Kengo Harato, Satoshi Oki, Yoshitake Yamada, Masaya Nakamura, Takeo Nagura, Masahiro Jinzaki

BMC musculoskeletal disorders (BMC Musculoskeletal Disorders)  23 ( 1 ) 253 - 253 2022.03

Accepted

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BACKGROUND: The classification of knee osteoarthritis is an essential clinical issue, particularly in terms of diagnosing early knee osteoarthritis. However, the evaluation of three-dimensional limb alignment on two-dimensional radiographs is limited. This study evaluated the three-dimensional changes induced by weight-bearing in the alignments of lower limbs at various stages of knee osteoarthritis. METHODS: Forty five knees of 25 patients (69.9 ± 8.9 years) with knee OA were examined in the study. CT images of the entire leg were obtained in the supine and standing positions using conventional CT and 320-row detector upright CT, respectively. Next, the differences in the three-dimensional alignment of the entire leg in the supine and standing positions were obtained using 3D-3D surface registration technique, and those were compared for each Kellgren-Lawrence grade. RESULTS: Greater flexion, adduction, and tibial internal rotation were observed in the standing position, as opposed to the supine position. Kellgren-Lawrence grades 1 and 4 showed significant differences in flexion, adduction, and tibial internal rotation between two postures. Grades 2 and 4 showed significant differences in adduction, while grades 1 and 2, and 1 and 3 showed significant differences in tibial internal rotation between standing and supine positions. CONCLUSIONS: Weight-bearing makes greater the three-dimensional deformities in knees with osteoarthritis. Particularly, greater tibial internal rotation was observed in patients with grades 2 and 3 compared to those with grade 1. The greater tibial internal rotation due to weight-bearing is a key pathologic feature to detect early osteoarthritic change in knees undergoing osteoarthritis.

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Impact of noise reduction on radiation dose reduction potential of virtual monochromatic spectral images: Comparison of phantom images with conventional 120 kVp images using deep learning image reconstruction and hybrid iterative reconstruction.

Masuda S, Yamada Y, Minamishima K, Owaki Y, Yamazaki A, Jinzaki M

European journal of radiology 149   110198 2022.02

ISSN  0720-048X

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Vector-field dynamic x-ray (VF-DXR) using optical flow method in patients with chronic obstructive pulmonary disease.

Takuya Hino, Akinori Tsunomori, Akinori Hata, Tomoyuki Hida, Yoshitake Yamada, Masako Ueyama, Tsutomu Yoneyama, Atsuko Kurosaki, Takeshi Kamitani, Kousei Ishigami, Takenori Fukumoto, Shoji Kudoh, Hiroto Hatabu

European radiology experimental (European Radiology Experimental)  6 ( 1 ) 4 - 4 2022.01

Accepted

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BACKGROUND: We assessed the difference in lung motion during inspiration/expiration between chronic obstructive pulmonary disease (COPD) patients and healthy volunteers using vector-field dynamic x-ray (VF-DXR) with optical flow method (OFM). METHODS: We enrolled 36 COPD patients and 47 healthy volunteers, classified according to pulmonary function into: normal, COPD mild, and COPD severe. Contrast gradient was obtained from sequential dynamic x-ray (DXR) and converted to motion vector using OFM. VF-DXR images were created by projection of the vertical component of lung motion vectors onto DXR images. The maximum magnitude of lung motion vectors in tidal inspiration/expiration, forced inspiration/expiration were selected and defined as lung motion velocity (LMV). Correlations between LMV with demographics and pulmonary function and differences in LMV between COPD patients and healthy volunteers were investigated. RESULTS: Negative correlations were confirmed between LMV and % forced expiratory volume in one second (%FEV1) in the tidal inspiration in the right lung (Spearman's rank correlation coefficient, rs = -0.47, p < 0.001) and the left lung (rs = -0.32, p = 0.033). A positive correlation between LMV and %FEV1 in the tidal expiration was observed only in the right lung (rs = 0.25, p = 0.024). LMVs among normal, COPD mild and COPD severe groups were different in the tidal respiration. COPD mild group showed a significantly larger magnitude of LMV compared with the normal group. CONCLUSIONS: In the tidal inspiration, the lung parenchyma moved faster in COPD patients compared with healthy volunteers. VF-DXR was feasible for the assessment of lung parenchyma using LMV.

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Accuracy of ultra-high-resolution computed tomography with a 0.3-mm detector for quantitative assessment of coronary artery stenosis grading in comparison with conventional computed tomography: A phantom study.

Minoru Yamada, Yoshitake Yamada, Takehiro Nakahara, Shigeo Okuda, Takayuki Abe, Sachio Kuribayashi, Masahiro Jinzaki

Journal of cardiovascular computed tomography (Journal of Cardiovascular Computed Tomography)  16 ( 3 ) 239 - 244 2021.11

Accepted,  ISSN  1934-5925

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BACKGROUND: The development of ultra-high-resolution CT (U-HRCT) is expected to improve the accuracy of coronary stenosis evaluation. This study aimed to evaluate the accuracy of the stenosis severities of coronary artery phantoms estimated using U-HRCT by comparing them to those estimated with conventional CT. METHODS: Coronary artery phantoms with non-calcified and calcified lesions were scanned with conventional CT (64-row ​× ​0.625 ​mm) and U-HRCT (32-row ​× ​0.3125 ​mm). The coronary artery phantoms had lumen diameters of 2.0, 3.0, and 4.0 ​mm with non-calcified lesions representing 0%, 25%, 50%, and 75% stenosis and 3.0 and 4.0 ​mm with calcified lesions representing 0%, 25%, 50%, and 75% stenosis. The lumen diameters at the stenotic and non-stenotic regions were measured, and the stenosis severities were compared with the true values. RESULTS: For non-calcified lesions, conventional CT significantly underestimated the stenosis severity in the phantom showing 75% stenosis with lumen diameters of 2.0 and 3.0 ​mm (p ​< ​0.05), while the estimated stenosis severities were not significantly different from the true values at all settings with U-HRCT. For the calcified lesions, conventional CT overestimated the stenosis severities at all settings (p ​< ​0.05), while U-HRCT yielded estimations closer to the true values, although still with some overestimation (p ​< ​0.05). CONCLUSION: By using U-HRCT, the estimated stenosis severities of the coronary artery with non-calcified lesion become almost equal to the true value, while those with calcified lesion are still overestimated although they become closer to the true value.

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Clinical Utility of the Electrocardiographic P-Wave Axis in Patients with Chronic Obstructive Pulmonary Disease.

Shiro Otake, Shotaro Chubachi, Shingo Nakayama, Kaori Sakurai, Hidehiro Irie, Mizuha Hashiguchi, Yuji Itabashi, Yoshitake Yamada, Masahiro Jinzaki, Mitsuru Murata, Hidetoshi Nakamura, Koichiro Asano, Koichi Fukunaga

Respiration; international review of thoracic diseases (Respiration)  101 ( 4 ) 1 - 8 2021.11

Accepted,  ISSN  0025-7931

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BACKGROUND: The vertical P-wave axis on electrocardiography (ECG) is a useful criterion for screening patients with chronic obstructive pulmonary disease (COPD). This study aimed to investigate the clinical characteristics of patients with COPD with a vertical P-wave axis as they have not yet been elucidated. METHODS: Keio University and its affiliated hospitals conducted an observational COPD cohort study over 3 years. We analyzed 201 patients using ECG and chest computed tomography. RESULTS: The severity of airflow limitation was higher in patients with a P-wave axis >75° than in those with a P-wave axis ≤75°. Patients with a P-wave axis >75° exhibited significantly higher total COPD assessment test scores and increased St. George's Respiratory Questionnaire total, activity, and impact scores than those with a P-wave axis ≤75°. The incidence of exacerbations over 1 and 3 years was significantly higher in patients with a P-wave axis >75° than in those with a P-wave axis ≤75°. The optimal cutoff for the P-wave axis for a percentage of the predicted forced expiratory volume in 1 s <50% and future exacerbations over 3 years was 70° (the areas under the curve [AUC]: 0.788; sensitivity: 65.3%; specificity: 78.3%) and 79° (AUC: 0.642; sensitivity: 36.7%; specificity: 92.6%). The ratio of the low attenuation area was also significantly higher in patients with a P-wave axis >75° than in those with a P-wave axis ≤75°. However, the ratio of the airway wall area did not differ between the 2 groups. CONCLUSIONS: Patients with COPD with a vertical P-wave axis exhibited severe airflow limitation and emphysema, a worse health status, and more frequent exacerbation than patients without a vertical P-wave. Detection of the vertical P-wave axis by ECG is beneficial for the management of patients with COPD.

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Analysis of Lap Belt Fit to Human Subjects using CT Images.

Yoshihiko Tanaka, Atsushi Nakashima, Haijie Feng, Koji Mizuno, Minoru Yamada, Yoshitake Yamada, Yoichi Yokoyama, Masahito Jinzaki

Stapp car crash journal (Stapp car crash journal)  65   49 - 90 2021.11

Accepted,  ISSN  1532-8546

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In vehicle collisions, the lap belt should engage the anterior superior iliac spine (ASIS). In this study, threedimensional (3D) shapes of bones and soft tissues around the pelvis were acquired using a computed tomography (CT) scan of 10 male and 10 female participants wearing a lap belt. Standing, upright sitting, and reclined postures were scanned using an upright CT and a supine CT scan system. In the upright sitting posture, the thigh height was larger with a higher BMI while the ASIS height did not change significantly with BMI. As a result, the height of the ASIS relative to the thigh (ASIS-thigh height) became smaller as the BMI increased. Because the thigh height of females was smaller than that of males, the ASIS-thigh height was larger for females than for males. As the ASIS-thigh height was larger, the overlap of the lap belt with the ASIS increased. Thus, the lap belt overlapped more with the ASIS for the females than for the males. The abdomen outer shape is characterized by the trouser cord formed valley, the torso/thigh junction, and the anterior convexity formed between them depending on the adipose tissues. The abdomen outer shapes changed from the standing, the reclined posture to the upright sitting posture. In the reclined sitting posture, the lap belt is positioned upward and rearward relative to the ASIS, and the overlap of the lap belt with the ASIS was smaller compared to the upright posture.

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Determining the validity and reliability of spinopelvic parameters through comparing standing whole spinal radiographs and upright computed tomography images.

Naruhito Fujita, Mitsuru Yagi, Kota Watanabe, Masaya Nakamura, Morio Matsumoto, Yoichi Yokoyama, Minoru Yamada, Yoshitake Yamada, Takeo Nagura, Masahiro Jinzaki

BMC musculoskeletal disorders (BMC Musculoskeletal Disorders)  22 ( 1 ) 899 - 899 2021.10

Accepted

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BACKGROUND: Standing whole spinal radiographs are used to evaluate spinal alignment in adult spinal deformity (ASD), yet some studies have reported that pelvic incidence, pelvic tilt, and thoracic kyphosis (TK) intra- and inter-observer reliability is low. This study aimed to evaluate the accuracy of spinopelvic parameters through comparing standing whole spinal radiographs and upright CT images. METHODS: We enrolled 26 patients with ASD. All standing whole spinal posterior/anterior and lateral radiographs and upright whole spinal CT had been obtained in a natural standing position. Two examiners independently measured 13 radiographic parameters. Interclass correlation coefficients (ICCs) were used to analyze measurement intra- and inter-observer reliability. Paired t- and Pearson's correlation tests were used to analyze validity of the standing whole spinal radiographs. RESULTS: ICCs of upright CT were excellent in both intra- and inter-observer reliability. However, intra-observer ICCs for TK2-12, TK1-5, TK2-5, and TK5-12 on standing lateral radiographs were relatively low, as were inter-observer ICCs for TK2-12, TK1-5, TK2-5, and TK5-12. Concerning TK values, the difference between the radiographs and CT in TK1-12 and TK2-12 were 4.4 ± 3.1 and 6.6 ± 4.6, respectively, and TK values from T2 showed greater measurement error (p < 0.05). CONCLUSIONS: Upright CT showed excellent intra- and inter-observer reliability in the measurement of spinopelvic parameters. Measurement of TK with T2 on standing whole spinal radiographs resulted in a greater measurement error of up to 6.6°. Surgeons need to consider this when planning surgery and measuring postoperative TK changes in patients with ASD.

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Difference in the airway luminal area between the standing and supine positions using upright and conventional computed tomography.

Shunsuke Matsumoto, Yoshitake Yamada, Minoru Yamada, Shotaro Chubachi, Yoichi Yokoyama, Shiho Matsuoka, Akiko Tanabe, Yuki Niijima, Mitsuru Murata, Koichi Fukunaga, Masahiro Jinzaki

Clinical anatomy (New York, N.Y.) (Clinical Anatomy)  34 ( 8 ) 1150 - 1156 2021.07

Accepted,  ISSN  0897-3806

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No clinical studies to date have compared the airway luminal area between supine and standing positions. Our aim was therefore to compare the airway luminal area between these two positions on computed tomography (CT) and to determine its correlation with forced expiratory volume in 1 s (FEV1). Thirty-two asymptomatic volunteers underwent both conventional (supine position) and upright (standing position) CT during deep inspiration breath-holding. Pulmonary function tests were conducted on the same day. We measured the airway luminal area on CT in each position. Paired t-tests and Pearson's correlation coefficients were used for statistical analysis. The average luminal areas of the trachea, right and left main bronchi, and average third-generation airway were greater in the standing than the supine position by 3.4%, 6.1%, 5.5%, and 5.2%, respectively. The correlation coefficients between airway luminal areas and FEV1 tended to be higher in the standing than the supine position; this correlation was highest for the average third-generation airway (r = 0.70, P < 0.0001). The airway luminal areas of the trachea, bilateral main bronchi, and average third-generation airway were greater in the standing than the supine position. The average third-generation airway area in the standing position had the highest correlation with FEV1.

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【CT再入門-新技術で何がわかる?-】Dual energy CTの活用　肺塞栓症

田村 全, 山田 祥岳, 陣崎 雅弘

画像診断 ((株)Gakken)  41 ( 9 ) 984 - 985 2021.07

ISSN  0285-0524

【CT再入門-新技術で何がわかる?-】面検出器CTの活用　関節動態

山田 稔, 山田 祥岳, 横山 陽一, 石井 和典, 名倉 武雄, 陣崎 雅弘

画像診断 ((株)Gakken)  41 ( 9 ) 952 - 953 2021.07

ISSN  0285-0524

【CT再入門-新技術で何がわかる?-】立位CTの活用　鼠径ヘルニア

山田 祥岳, 山田 稔, 横山 陽一, 陣崎 雅弘

画像診断 ((株)Gakken)  41 ( 9 ) 1008 - 1009 2021.07

ISSN  0285-0524

【CT再入門-新技術で何がわかる?-】立位CTの活用　骨盤臓器脱

横山 陽一, 山田 祥岳, 山田 稔, 陣崎 雅弘

画像診断 ((株)Gakken)  41 ( 9 ) 1010 - 1011 2021.07

ISSN  0285-0524

【CT再入門-新技術で何がわかる?-】立位CTの活用　脊椎すべり症

山田 祥岳, 山田 稔, 横山 陽一, 名倉 武雄, 陣崎 雅弘

画像診断 ((株)Gakken)  41 ( 9 ) 1006 - 1007 2021.07

ISSN  0285-0524

Quantification of Adipose Tissue Around the Aortic Aneurysm　- At the Dawn of a New Era.

Okuda S, Yamada Y, Nakahara T, Jinzaki M

Circulation journal : official journal of the Japanese Circulation Society (一般社団法人 日本循環器学会)  85 ( 12 ) 2181 - 2183 2021.06

ISSN  1346-9843

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A rare case of COVID-19 infection with laryngeal involvement.

Masato Asaoka, Shotaro Chubachi, Yoshitake Yamada, Koichi Fukunaga

BMJ case reports (BMJ Case Reports)  14 ( 6 )  2021.06

Accepted

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Saphenous vein valve assessment utilizing upright CT to potentially improve graft assessment for bypass surgery.

Takehiro Nakahara, Minoru Yamada, Yoichi Yokoyama, Yoshitake Yamada, Keiichi Narita, Nobuaki Imanishi, Masataka Yamazaki, Hideyuki Shimizu, Jagat Narula, Masahiro Jinzaki

Scientific reports (Scientific Reports)  11 ( 1 ) 11602 - 11602 2021.06

Accepted

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Saphenous veins (SVs) are frequently employed as bypass grafts. The SV graft failure is predominantly seen at the valve site. Avoiding valves during vein harvest would help reduce graft failure. We endeavored to detect SV valves, tributaries, and vessel size employing upright computed tomography (CT) for the raw cadaver venous samples and in healthy volunteers. Five cadaver legs were scanned. Anatomical analysis showed 3.0 (IQR: 2.0-3.0) valves and 13.50 (IQR: 10.00-16.25) tributaries. The upright CT completely detected, compared to 2.0 (IQR: 1.5-2.5, p = 0.06) valves and 9.5 (IQR: 7.5-13.0, p = 0.13) tributaries by supine CT. From a total of 190 volunteers, 138 (men:75, women:63) were included. The number of valves from the SF junction to 35 cm were significantly higher in upright CT than in supine CT bilaterally [upright vs. supine, Right: 4 (IQR: 3-5) vs. 2 (IQR:1-2), p < 0.0001, Left: 4 (IQR: 3-5) vs. 2 (IQR: 1-2), p < 0.0001]. The number of tributaries and vessel areas per leg were also higher for upright compared with supine CT. Upright CT enables non-invasive detection of SV valves, tributaries, and vessel size. Although not tested here, it is expected that upright CT may potentially improve graft assessment for bypass surgery.

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