Details of a Researcher - Jinzaki, Masahiro

Papers - Jinzaki, Masahiro

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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 (European Journal of Radiology) 149 2022.04

ISSN 0720048X

Purpose: To assess the effects of deep learning image reconstruction (DLIR) and hybrid iterative reconstruction (HIR) on the image quality of virtual monochromatic spectral (VMS) images and to investigate the dose reduction potential of the VMS and conventional 120 kVp images. Methods: A cylindrical phantom simulating an adult abdomen was used. The contrast was set to 60 (medium) and 300 (high) Hounsfield units. CT acquisitions were performed at three dose levels: 12, 9, and 6 mGy. Images were reconstructed via filtered back projection (FBP), DLIR, and HIR. The noise power spectrum (NPS) and task transfer function (TTF) were measured, and the system performance (SP) function was calculated (TTF2/NPS). Results: The noise magnitudes at low spatial frequencies with DLIR and HIR were lower than that with FBP by 45.6% and 24.4%, respectively. Compared to the FBP results, the TTF values at 50% with DLIR at medium and high contrast changed by –13.2% and +25.3% with the VMS images and –2.0% and +9.3% with the 120 kVp images, respectively. In the VMS and 120 kVp images, compared to the SP values of 12 mGy FBP images, SP values of 6 mGy DLIR images decreased at medium contrast and increased at high contrast. Conclusions: DLIR achieved better noise reduction than HIR. The spatial resolution of VMS-DLIR varied significantly depending on the contrast. The image quality of VMS-DLIR and 120 kVp-DLIR potentially decrease in medium contrast tasks and increase in high contrast tasks with 50% dose reduction.

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Does neoadjuvant chemotherapy have therapeutic benefit for node-positive upper tract urothelial carcinoma? Results of a multi-center cohort study

Shigeta K., Matsumoto K., Ogihara K., Murakami T., Anno T., Umeda K., Izawa M., Baba Y., Sanjo T., Shojo K., Tanaka N., Takeda T., Morita S., Kosaka T., Mizuno R., Arita Y., Akita H., Jinzaki M., Kikuchi E., Oya M.

Urologic Oncology: Seminars and Original Investigations (Urologic Oncology: Seminars and Original Investigations) 40 ( 3 ) 105.e19 - 105.e26 2022.03

ISSN 10781439

Objective: The indications of neoadjuvant chemotherapy (NAC) for lymph node-positive upper tract urothelial carcinoma (UTUC) have not been investigated regarding improved survival outcomes. Our specific aim was to compare the clinical outcomes of clinically node-positive UTUC patients who were treated by NAC followed by radical nephroureterectomy (RNU) or upfront RNU followed by adjuvant chemotherapy (AC). Materials and methods: Among 966 UTUC patients, we identified 89 with clinical nodal involvement who received either NAC before RNU nor AC after upfront RNU. Cox proportional hazard models were employed to evaluate the impact of chemotherapy modality on the oncological outcomes. Results: Of the patient cohort, 36 (40.4%) received NAC followed by RNU, whereas 53 (59.6%) underwent RNU followed by AC. Multivariate analysis revealed that tumor size ≥3 cm, clinical T4, and gemcitabine and cisplatin regimen were independent risk factors for disease recurrence, whereas NAC followed by RNU was an independent factor for favorable RFS. Furthermore, regarding cancer-specific survival (CSS), NAC followed by RNU remained an independent factor for favorable CSS. According to Kaplan-Meier analysis, the 1-year and 2-year RFS were 67.9% and 47.0%, respectively, in the NAC+RNU group, which were significantly higher than those in the RNU+AC group (43.9% and 24.6%, respectively, P = 0.006). Moreover, the 1-year and 2-year CSS were 80.5% and 64.2%, respectively, in the NAC+RNU group, which were higher than those in the RNU+AC group (68.6% and 48.2%, respectively, P = 0.016). Conclusion: For node-positive UTUC patients, NAC followed by RNU was more clinically beneficial than RNU followed by AC.

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Photoacoustic lymphangiography exhibits advantages over near-infrared fluorescence lymphangiography as a diagnostic tool in patients with lymphedema

Suzuki Y., Kajita H., Oh A., Urano M., Watanabe S., Sakuma H., Imanishi N., Tsuji T., Jinzaki M., Kishi K.

Journal of Vascular Surgery: Venous and Lymphatic Disorders (Journal of Vascular Surgery: Venous and Lymphatic Disorders) 10 ( 2 ) 454 - 462.e1 2022.03

ISSN 2213333X

Objective: Photoacoustic imaging is a new technique that can evaluate the vascular system using photoacoustic effects. The present study compared the ability of the new photoacoustic lymphangiography (PAL) method and more standard near-infrared fluorescence (NIRF) to image the lymphatic system in patients with secondary lymphedema after gynecological cancer surgery. Methods: Patients with secondary lymphedema in the lower extremities after gynecologic cancer surgery, who were assessed using PAL between May 2018 and January 2019, were recruited. NIRF was performed first using 5.0 mg/mL of indocyanine green injected using a 0.2-cc 30-gauge needle. Correlations between NIRF and PAL findings on patient images were subsequently examined. Results: Seventeen patients with secondary lymphedema were enrolled. The mean age of the patients was 61 ± 11 years. The imaging sites were the medial lower leg in 15 patients, the posterior lower leg in 9 patients, the lateral lower leg in 7 patients, the medial knee in 4 patients, and other areas in 3 patients. A total of 38 pictures were obtained. Five distinct lymphatic patterns were observed over the entire sample using PAL: straight, winding, spiderweb, nebulous, and black-out pattern. Eighteen of the 24 limbs (75%) that exhibited a linear pattern in NIRF exhibited a straight pattern in PAL, and 19 of the 20 limbs (95%) that exhibited a splash pattern in NIRF exhibited a winding or spiderweb pattern in PAL. Eight limbs exhibiting diffuse patterns without linear or splash patterns with NIRF were all nebulous or black-out patterns in PAL. This suggests that more severe lymphatic degeneration was associated with poorer visualization in PAL. Conclusions: NIRF plays an important role in lymphedema treatment. In the present study, various PAL patterns were compared with those observed using NIRF. PAL provided clearer images including transectional views, which were not available using NIRF, and may promote further understanding of the changes in the lymphatic structure and function in patients with secondary lymphedema.

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Lower limb lymphedema staging based on magnetic resonance lymphangiography

Soga S., Onishi F., Mikoshi A., Okuda S., Jinzaki M., Shinmoto H.

Journal of Vascular Surgery: Venous and Lymphatic Disorders (Journal of Vascular Surgery: Venous and Lymphatic Disorders) 10 ( 2 ) 445 - 453.e3 2022.03

ISSN 2213333X

Objective: Dermal backflow (DBF) and reduced lymphatic visualization are common findings of lymphedema on various imaging modalities. However, there is a lack of knowledge about how these findings vary with the anatomic location and severity of lymphedema, and previous reports using indocyanine green lymphography or lymphoscintigraphy show variable results. Magnetic resonance lymphangiography (MRL) is expected to clarify this clinical question due to its superior ability for lymphatic visualization. This retrospective study aimed to investigate the following: (1) Are there any characteristic patterns for DBF and lymphatics' visualization, depending on the anatomic location within lower limbs and severity of lymphedema? (2) Is it possible to classify the severity of lymphedema based on MRL findings? Methods: Two radiologists performed consensus readings of MRL of 56 patients (112 limbs) with lower-limb lymphedema. The frequency of visualized DBF and lymphatics was analyzed in six regions in each lower limb. The results were compared with the International Society of Lymphology clinical stages and etiology of lymphedema. Characteristic findings were categorized and compared with the clinical stage and duration of lymphedema. Results: DBF and lymphatics were observed more frequently in the distal regions than the proximal regions of lower limbs. DBF appeared more frequently as the clinical stage increased, reaching statistical significance (P < 10−3) between stages 0 or I and II. DBF above the knee joint was rarely observed (0.48%) in early stages (0 and I) but appeared more frequently (13.5%, P < 10−5) in stage II. Lymphatics appeared less frequently as the stage progressed, with significant differences (P <.05) between stages I and II and between II and III. The frequency of lymphatics above the knee joint decreased significantly (P <.05) between stages I and II and between II and III as the stage progressed, reaching 0% in stage III. An MRL staging was proposed and showed significant positive correlations with the clinical stage (r = 0.79, P <.01) and the duration of lymphedema (r = 0.57, P <.01). Conclusions: MRL-specific patterns of DBF and lymphatics that depended on the site within the lower limb and clinical stage were shown. The DBF pattern differed from those observed in previous studies with other imaging techniques. The proposed MRL staging based on these characteristic findings allows new stratification of patients with lymphedema. Combined with its excellent ability to visualize lymphatic anatomy, MRL could enable a more detailed understanding of individual patient's pathology, useful for determining the most appropriate treatment.

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Three-Dimensional Innate Mobility of the Human Foot on Coronally-Wedged Surfaces Using a Biplane X-Ray Fluoroscopy

Negishi T., Nozaki S., Ito K., Seki H., Hosoda K., Nagura T., Imanishi N., Jinzaki M., Ogihara N.

Frontiers in Bioengineering and Biotechnology (Frontiers in Bioengineering and Biotechnology) 10 2022.02

Improving our understanding on how the foot and ankle joints kinematically adapt to coronally wedged surfaces is important for clarifying the pathogenetic mechanism and possible interventions for the treatment and prevention of foot and lower leg injuries. It is also crucial to interpret the basic biomechanics and functions of the human foot that evolved as an adaptation to obligatory bipedal locomotion. Therefore, we investigated the three-dimensional (3D) bone kinematics of human cadaver feet on level (0°, LS), medially wedged (−10°, MWS), and laterally wedged (+10°, LWS) surfaces under axial loading using a biplanar X-ray fluoroscopy system. Five healthy cadaver feet were axially loaded up to 60 kg (588N) and biplanar fluoroscopic images of the foot and ankle were acquired during axial loading. For the 3D visualization and quantification of detailed foot bony movements, a model-based registration method was employed. The results indicated that the human foot was more largely deformed from the natural posture when the foot was placed on the MWS than on the LWS. During the process of human evolution, the human foot may have retained the ability to more flexibly invert as in African apes to better conform to MWS, possibly because this ability was more adaptive even for terrestrial locomotion on uneven terrains. Moreover, the talus and tibia were externally rotated when the foot was placed on the MWS due to the inversion of the calcaneus, and they were internally rotated when the foot was placed on the LWS due to the eversion of the calcaneus, owing to the structurally embedded mobility of the human talocalcaneal joint. Deformation of the foot during axial loading was relatively smaller on the MWS due to restricted eversion of the calcaneus. The present study provided new insights about kinematic adaptation of the human foot to coronally wedged surfaces that is inherently embedded and prescribed in its anatomical structure. Such detailed descriptions may increase our understanding of the pathogenetic mechanism and possible interventions for the treatment and prevention of foot and lower leg injuries, as well as the evolution of the human foot.

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Diagnostic performance of the vesical imaging-reporting and data system for detecting muscle-invasive bladder cancer in real clinical settings: Comparison with diagnostic cystoscopy

Kufukihara R., Kikuchi E., Shigeta K., Ogihara K., Arita Y., Akita H., Suzuki T., Abe T., Mizuno R., Jinzaki M., Oya M.

Urologic Oncology: Seminars and Original Investigations (Urologic Oncology: Seminars and Original Investigations) 40 ( 2 ) 61.e1 - 61.e8 2022.02

ISSN 10781439

Purpose: We herein compared the diagnostic performance of Vesical Imaging-Reporting and Data System (VI-RADS) scoring with diagnostic cystoscopy and evaluated diagnostic accuracies based on tumor locations. Materials and Methods: Among 112 bladder cancer patients who underwent multiparametric magnetic resonance imaging and diagnostic cystoscopy preoperatively to detect bladder cancer, 61 were analyzed. VI-RADS was categorized into 5 stages by 2 radiologists (R1 and R2). Cut-off values ≥3 indicated muscle-invasive bladder cancer (MIBC). Muscle invasion (MI) was visually evaluated using diagnostic cystoscopy by 2 urologists (U1 and U2). The sensitivity and specificity of VI-RADS scores and diagnostic cystoscopy for diagnosing MI were compared. Results: 16 patients (26.2%) were pathologically diagnosed with MIBC. Regarding MI diagnostic accuracy, the sensitivity/specificity of VI-RADS scores were 93.8/88.9% by R1 and 87.5/86.7% by R2, while those of diagnostic cystoscopy were 56.3/68.9% by U1 and 68.8/84.4% by U2. Therefore, the diagnostic accuracy of VI-RADS was significantly higher than that of cystoscopy, particularly for tumors located on the bladder neck, trigone, dome, and posterior and anterior walls. Over- and under-diagnosis rates were higher with VI-RADS than with diagnostic cystoscopy (25.9% vs. 14.8%) for tumors located on the lateral wall or ureteral orifice. Conclusion: VI-RADS had superior diagnostic performance for detecting MI, especially in tumors located at the bladder neck/trigone/dome/posterior and anterior wall. However, VI-RADS was inferior to cystoscopy in terms of MI detection for tumors located on the lateral wall or ureteral orifice. Therefore, a combination of diagnostic tools is recommended for the accurate staging of these tumors.

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Comparative Functional Morphology of Human and Chimpanzee Feet Based on Three-Dimensional Finite Element Analysis

Ito K., Nakamura T., Suzuki R., Negishi T., Oishi M., Nagura T., Jinzaki M., Ogihara N.

Frontiers in Bioengineering and Biotechnology (Frontiers in Bioengineering and Biotechnology) 9 2022.01

To comparatively investigate the morphological adaptation of the human foot for achieving robust and efficient bipedal locomotion, we develop three-dimensional finite element models of the human and chimpanzee feet. Foot bones and the outer surface of the foot are extracted from computer tomography images and meshed with tetrahedral elements. The ligaments and plantar fascia are represented by tension-only spring elements. The contacts between the bones and between the foot and ground are solved using frictionless and Coulomb friction contact algorithms, respectively. Physiologically realistic loading conditions of the feet during quiet bipedal standing are simulated. Our results indicate that the center of pressure (COP) is located more anteriorly in the human foot than in the chimpanzee foot, indicating a larger stability margin in bipedal posture in humans. Furthermore, the vertical free moment generated by the coupling motion of the calcaneus and tibia during axial loading is larger in the human foot, which can facilitate the compensation of the net yaw moment of the body around the COP during bipedal locomotion. Furthermore, the human foot can store elastic energy more effectively during axial loading for the effective generation of propulsive force in the late stance phase. This computational framework for a comparative investigation of the causal relationship among the morphology, kinematics, and kinetics of the foot may provide a better understanding regarding the functional significance of the morphological features of the human foot.

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A novel technique for automating stiffness measurement and emphasizing the main wave: Coherent-wave auto-selection (CHASE)

Ito D., Numano T., Habe T., Mizuhara K., Arita Y., Soga S., Okuda S., Jinzaki M.

Magnetic Resonance Imaging (Magnetic Resonance Imaging) 85 133 - 140 2022.01

ISSN 0730725X

This study aims to develop and assess a new automated processing technique in MR elastography (MRE), namely coherent-wave auto-selection (CHASE). CHASE enables automatic selection of the region of interest (ROI) for stiffness measurement by extraction of the coherent wave region (CHASE ROI), and it improves the reconstruction of stiffness by a directional filter oriented along the main wave in each pixel (CHASE filtering). In this study, MRE of a phantom and of the liver of four healthy volunteers was performed. To investigate the potential of CHASE, this study assessed the CHASE according to three indices through the phantom study: 1) agreement on the ROI settings between CHASE and expert observers, 2) noise dependency, and 3) effect of the CHASE on stiffness variability within the CHASE ROI. The agreements on the ROI settings were analyzed by Cohen's kappa coefficient (κ). The noise dependency was analyzed by the mean absolute percentage errors (MAPEs) within the ROI between low (20%–80% amplitudes) and high vibration amplitudes (100% amplitude). The stiffness variability was assessed by standard deviation (SD) within the ROI. In the volunteer study, agreements on the ROI settings (or stiffness value) and stiffness variability within the CHASE ROI were assessed using κ-value (or intraclass correlation coefficient: ICC) and coefficient of variation, respectively. The results showed close agreement on the ROI settings and stiffness (κ-value: greater than 0.61 in both the phantom and volunteer studies, ICC: 0.97 in the volunteer study). The MAPEs within the CHASE ROI were much smaller than those in the whole region of the phantom (CHASE ROI vs. the whole region at 20% amplitude: 10.3% vs. 50.8%). Moreover, in both the phantom and volunteer studies, the stiffness variation within the CHASE ROI was smaller in the elastogram processed with CHASE filtering than in the unprocessed one. Our results demonstrated that the CHASE has high robustness against noise and the potential to provide ROI settings for stiffness measurement comparable to expert observers, as well as improve the reconstruction of stiffness.

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Development of In Vitro Endothelialised Stents - Review -

Tsukada J., Mela P., Jinzaki M., Tsukada H., Schmitz-Rode T., Vogt F.

Stem Cell Reviews and Reports (Stem Cell Reviews and Reports) 18 ( 1 ) 179 - 197 2022.01

ISSN 26293269

Endovascular treatment is prevalent as a primary treatment for coronary and peripheral arterial diseases. Although the introduction of drug-eluting stents (DES) dramatically reduced the risk of in-stent restenosis, stent thrombosis persists as an issue. Notwithstanding improvements in newer generation DES, they are yet to address the urgent clinical need to abolish the late stent complications that result from in-stent restenosis and are associated with late thrombus formation. These often lead to acute coronary syndromes with high mortality in coronary artery disease and acute limb ischemia with a high risk of limb amputation in peripheral arterial disease. Recently, a significant amount of research has focused on alternative solutions to improve stent biocompatibility by using tissue engineering. There are two types of tissue engineering endothelialisation methods: in vitro and in vivo. To date, commercially available in vivo endothelialised stents have failed to demonstrate antithrombotic or anti-stenosis efficacy in clinical trials. In contrast, the in vitro endothelialisation methods exhibit the advantage of monitoring cell type and growth prior to implantation, enabling better quality control. The present review discusses tissue-engineered candidate stents constructed by distinct in vitro endothelialisation approaches, with a particular focus on fabrication processes, including cell source selection, stent material composition, stent surface modifications, efficacy and safety evidence from in vitro and in vivo studies, and future directions. Graphical abstract: [Figure not available: see fulltext.]

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Synthetic magnetic resonance imaging for primary prostate cancer evaluation: Diagnostic potential of a non-contrast-enhanced bi-parametric approach enhanced with relaxometry measurements

Arita Y., Akita H., Fujiwara H., Hashimoto M., Shigeta K., Kwee T.C., Yoshida S., Kosaka T., Okuda S., Oya M., Jinzaki M.

European Journal of Radiology Open (European Journal of Radiology Open) 9 2022.01

Purpose: Bi-parametric magnetic resonance imaging (bpMRI) with diffusion-weighted images has wide utility in diagnosing clinically significant prostate cancer (csPCa). However, bpMRI yields more false-negatives for PI-RADS category 3 lesions than multiparametric (mp)MRI with dynamic-contrast-enhanced (DCE)-MRI. We investigated the utility of synthetic MRI with relaxometry maps for bpMRI-based diagnosis of csPCa. Methods: One hundred and five treatment-naïve patients who underwent mpMRI and synthetic MRI before prostate biopsy for suspected PCa between August 2019 and December 2020 were prospectively included. Three experts and three basic prostate radiologists evaluated the diagnostic performance of conventional bpMRI and synthetic bpMRI for csPCa. PI-RADS version 2.1 category 3 lesions were identified by consensus, and relaxometry measurements (T1-value, T2-value, and proton density [PD]) were performed. The diagnostic performance of relaxometry measurements for PI-RADS category 3 lesions in peripheral zone was compared with that of DCE-MRI. Histopathological evaluation results were used as the reference standard. Statistical analysis was performed using the areas under the receiver operating characteristic curve (AUC) and McNemar test. Results: In 102 patients without significant MRI artefacts, the diagnostic performance of conventional bpMRI was not significantly different from that of synthetic bpMRI for all readers (p = 0.11–0.79). The AUCs of the combination of T1-value, T2-value, and PD (T1 + T2 + PD) for csPCa in peripheral zone for PI-RADS category 3 lesions were 0.85 for expert and 0.86 for basic radiologists, with no significant difference between T1 + T2 + PD and DCE-MRI for both expert and basic radiologists (p = 0.29–0.45). Conclusion: Synthetic MRI with relaxometry maps shows promise for contrast media-free evaluation of csPCa.

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Multisystem Imaging Manifestations of Kawasaki Disease

Tsujioka Y., Handa A., Nishimura G., Miura M., Yokoyama K., Sato K., Handa H., Jinzaki M., Nosaka S., Kono T.

Radiographics (Radiographics) 42 ( 1 ) 268 - 288 2022.01

ISSN 02715333

Kawasaki disease (KD) is a common pediatric vasculitis syndrome involving medium-and small-sized arteries that is especially preva-lent in early childhood (ie, age 6 months to 5 years). The diagnosis of KD is made on the basis of clinical features, such as fever, char-acteristic mucocutaneous changes, and nonsuppurative cervical lymphadenopathy. However, early diagnosis is often challenging because many children with KD present with atypical symptoms. The most serious complication of KD is coronary artery aneurysm caused by coronary arteritis. Prompt intravenous immunoglobu-lin therapy reduces the risk of cardiac morbidity. In addition, the systemic extension of KD-related vasculitis during the acute phase causes a variety of multisystem manifestations, including encepha-lopathy, stroke, retropharyngeal edema, pericarditis, myocarditis, KD shock syndrome, pulmonary lesions, intestinal pseudo-obstruc-tion, gallbladder hydrops, arthritis, and myositis. These complications tend to be more common in affected children with atypical presentation. Radiologists can play an important role in the timely identification of diverse KD-associated morbidities and thus may contribute to the early diagnosis of atypical KD.

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BCG osteomyelitis: tips for diagnosis

Tsujioka Y., Nozaki T., Nishimura G., Miyazaki O., Jinzaki M., Kono T.

Skeletal Radiology (Skeletal Radiology) 2022

ISSN 03642348

Objective: To report the clinical and imaging characteristics of BCG-osteomyelitis, and compare them with those of pyogenic osteomyelitis. Materials and methods: Clinical and imaging findings were retrospectively evaluated in 14 children with BCG osteomyelitis, including 3 with Mendelian susceptibility to mycobacterial diseases (MSMD), and in 40 children with pyogenic osteomyelitis, using Fisher exact and Mann-Whitney U tests. Results: BCG-osteomyelitis was an indolent inflammatory disease of young children (mean age 15.5 months). Immunocompetent patients came to medical attention over months after vaccination, while patients with MSMD much earlier (the average time lapse: 13.7 vs. 5.0 months). The former manifested with a slowly progressive, painless mass with only mildly increased acute-phase reactants, while the latter started with lymphadenitis with significant inflammatory reactions and later developed osteomyelitis. These clinical scenarios contrasted with acute febrile illness in pyogenic osteomyelitis. The imaging findings were identical in both immunocompetent and MSMD groups; however, the former showed monoostotic involvement, while the latter polyostotic affliction. The typical imaging finding of BCG-osteomyelitis comprises a large intraosseous abscess with modest reactive edema commonly associated with transphyseal extension from the metaphysis to the epiphysis, contrasting with the manifestation of pyogenic osteomyelitis; size of abscess (p=0.028), pattern of abscess extension (p<0.001), and extent of surrounding edema (p<0.001). Conclusions: BCG-osteomyelitis should be suspected in children under 2 years of age with insidious osteomyelitis, accompanied with characteristic imaging findings. Polyostotic BCG osteomyelitis is highly suggestive of MSMD. Awareness of the distinctive features of BCG-osteomyelitis enables the early diagnosis and timely therapeutic intervention.

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Differences in airway lumen area between supine and upright computed tomography in patients with chronic obstructive pulmonary disease

Chubachi S., Yamada Y., Yamada M., Yokoyama Y., Tanabe A., Matsuoka S., Niijima Y., Yamasawa W., Irie H., Murata M., Fukunaga K., Jinzaki M.

Respiratory Research (Respiratory Research) 22 ( 1 ) 2021.12

ISSN 14659921

Background: No clinical studies to date have compared the inspiratory and expiratory airway lumen area between supine and standing positions. Thus, the aims of this study were twofold: (1) to compare inspiratory and expiratory airway lumen area (IAA and EAA, respectively) on computed tomography (CT) among supine and standing positions; and (2) to investigate if IAA and EAA are associated with lung function abnormality in patients with chronic obstructive pulmonary disease (COPD). Methods: Forty-eight patients with COPD underwent both low-dose conventional (supine position) and upright CT (standing position) during inspiration and expiration breath-holds and a pulmonary function test (PFT) on the same day. We measured the IAA and EAA in each position. Results: For the trachea to the third-generation bronchi, the IAA was significantly larger in the standing position than in the supine position (4.1–4.9% increase, all p < 0.05). The EAA of all bronchi was significantly larger in the standing position than in the supine position (9.7–62.5% increases, all p < 0.001). The correlation coefficients of IAA in the standing position and forced expiratory volume in 1 s were slightly higher than those in the supine position. The correlation coefficients of EAA or EAA/IAA in the standing position and residual volume, and the inspiratory capacity/total lung capacity ratio were higher than those in the supine position. Conclusions: Airway lumen areas were larger in the standing position than in the supine position. IAAs reflect airway obstruction, and EAAs reflect lung hyperinflation. Upright CT might reveal these abnormalities more precisely. Trial registration University Hospital Medical Information Network (UMIN 000026587), Registered 17 March 2017. URL: https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000030456.

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Three-dimensional evaluation of the coccyx movement between supine and standing positions using conventional and upright computed tomography imaging

Yagi F., Yamada Y., Yamada M., Yokoyama Y., Mukai K., Nakahara T., Narita K., Jinzaki M.

Scientific Reports (Scientific Reports) 11 ( 1 ) 2021.12

Currently, no three-dimensional reference data exist for the normal coccyx in the standing position on computed tomography (CT); however, this information could have utility for evaluating patients with coccydynia and pelvic floor dysfunction. Thus, we aimed to compare coccygeal parameters in the standing versus supine positions using upright and supine CT and evaluate the effects of sex, age, and body mass index (BMI) on coccygeal movement. Thirty-two healthy volunteers underwent both upright (standing position) and conventional (supine position) CT examinations. In the standing position, the coccyx became significantly longer and straighter, with the tip of the coccyx moving backward and downward (all p < 0.001). Additionally, the coccygeal straight length (standing/supine, 37.8 ± 7.1/35.7 ± 7.0 mm) and sacrococcygeal straight length (standing/supine, 131.7 ± 11.2/125.0 ± 10.7 mm) were significantly longer in the standing position. The sacrococcygeal angle (standing/supine, 115.0 ± 10.6/105.0 ± 12.5°) was significantly larger, while the lumbosacral angle (standing/supine, 21.1 ± 5.9/25.0 ± 4.9°) was significantly smaller. The migration length of the tip of the coccyx (mean, 7.9 mm) exhibited a moderate correlation with BMI (r = 0.42, p = 0.0163). Our results may provide important clues regarding the pathogenesis of coccydynia and pelvic floor dysfunction.

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Effect of gravity on brain structure as indicated on upright computed tomography

Yokoyama Y., Yamada Y., Kosugi K., Yamada M., Narita K., Nakahara T., Fujiwara H., Toda M., Jinzaki M.

Scientific Reports (Scientific Reports) 11 ( 1 ) 2021.12

We aimed to use upright computed tomography (CT) to depict posture-related changes in the brain tissue under normal gravity. Thirty-two asymptomatic volunteers underwent upright CT in the sitting position and conventional CT in the supine position on the same day. We compared the shift of the pineal body, cerebellar tonsil, the length of pituitary stalk, optic nerve sheath area and perimeter (ONSA and ONSP, respectively), and lateral ventricular volume between the supine and sitting positions. We also compared shape changes of the cerebrospinal fluid (CSF) spaces at different sites between both positions. In the sitting position, the pineal body shifted 0.68 ± 0.27 mm in the ventral direction and 0.76 ± 0.24 mm in the caudal direction, the length of pituitary stalk decreased by 1.23 ± 0.71 mm, the cerebellar tonsil descended by 2.10 ± 0.86 mm, the right ONSA decreased by 15.21 ± 6.54%, the left ONSA decreased by 15.30 ± 7.37%, the right ONSP decreased by 8.52 ± 3.91%, the left ONSP decreased by 8.20 ± 4.38%, and the lateral ventricular volume decreased by 5.07 ± 3.24% (all P < 0.001). We also observed changes in the shape of CSF spaces with changes in posture. We concluded that the intracranial structure of healthy subjects and volume of ventricles changed according to posture on Earth.

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Characteristics of chronic obstructive pulmonary disease patients with robust progression of emphysematous change

Tsutsumi A., Chubachi S., Irie H., Sasaki M., Yamada Y., Sugiura H., Jinzaki M., Nakamura H., Asano K., Betsuyaku T., Fukunaga K.

Scientific Reports (Scientific Reports) 11 ( 1 ) 2021.12

Emphysema is a major pathological change in chronic obstructive pulmonary disease (COPD). However, the annual changes in the progression of emphysematous have not been investigated. We aimed to determine possible baseline predicting factors of the change in emphysematous progression in a subgroup of COPD patients who demonstrated rapid progression. In this observational study, we analyzed patients with COPD who were followed up by computed tomography (CT) at least two times over a 3-year period (n = 217). We divided the annual change in the low attenuation area percentage (LAA%) into quartiles and defined a rapid progression group (n = 54) and a non-progression group (n = 163). Predictors of future changes in emphysematous progression differed from predictors of high LAA% at baseline. On multivariate logistic regression analysis, low blood eosinophilic count (odds ratio [OR], 3.22; P = 0.04) and having osteoporosis (OR, 2.13; P = 0.03) were related to rapid changes in emphysematous progression. There was no difference in baseline nutritional parameters, but nutritional parameters deteriorated in parallel with changes in emphysematous progression. Herein, we clarified the predictors of changes in emphysematous progression and concomitant deterioration of nutritional status in COPD patients.

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Unbiased, comprehensive analysis of Japanese health checkup data reveals a protective effect of light to moderate alcohol consumption on lung function

Makino K., Shimizu-Hirota R., Goda N., Hashimoto M., Kawada I., Kashiwagi K., Hirota Y., Itoh H., Jinzaki M., Iwao Y., Ko M., Ko S., Takaishi H.

Scientific Reports (Scientific Reports) 11 ( 1 ) 2021.12

The overall effect of lifestyle habits, such as alcohol consumption, on general health remains controversial and it is important to clarify how such habits affect aging-related health impairments. To discover novel impacts of lifestyle on general health, we employed a mathematical approach to perform a comprehensive, unbiased, cross-sectional analysis of data from 6036 subjects who participated in a Japanese health checkup. Notably, we found that moderate alcohol consumption was positively correlated with lung function, muscle mass, and strength. Health checkup data were collected periodically from the same subjects. These people were light to moderate drinkers who had high health awareness and were basically free of major underlying diseases. We next analyzed 5 years of data from 1765 of these subjects. We found that higher baseline alcohol consumption, as well as increased alcohol intake over 5 years attenuated time-related deterioration of forced vital capacity without affecting total lung volume. This effect was independent of smoking. Our study suggests a possible protective effect of moderate amounts of alcohol on lung function, due to increased muscle mass/strength and forced vital capacity.

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

Nakahara T., Yamada M., Yokoyama Y., Yamada Y., Narita K., Imanishi N., Yamazaki M., Shimizu H., Narula J., Jinzaki M.

Scientific Reports (Scientific Reports) 11 ( 1 ) 2021.12

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

Fujita N., Yagi M., Watanabe K., Nakamura M., Matsumoto M., Yokoyama Y., Yamada M., Yamada Y., Nagura T., Jinzaki M.

BMC Musculoskeletal Disorders (BMC Musculoskeletal Disorders) 22 ( 1 ) 2021.12

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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特集 AI と心臓病診療日常診療への可能性を探る企画にあたって

陣崎雅弘

Heart View (メジカルビュー社) 25 ( 11 ) 1015 - 1015 2021.11

ISSN 1342-6591

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