Publications by authors named "Hajime Sakuma"

This study aims to develop a computerized classification method for significant coronary artery stenosis on whole-heart coronary magnetic resonance angiography (WHCMRA) images using a 3D convolutional neural network (3D-CNN) with attention mechanisms. The dataset included 951 segments from WHCMRA images of 75 patients who underwent both WHCMRA and invasive coronary angiography (ICA). Forty-two segments with significant stenosis (luminal diameter reduction 75%) on ICA were annotated on WHCMRA images by an experienced radiologist, whereas 909 segments without it were annotated at representative sites.

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Brush sign (BS) was first reported as prominent hypointensity of deep medullary veins and subependymal veins on T2*-weighted images at 3 T MRI in patients with acute stroke in the territory of the middle cerebral artery. Subsequently, BS in central nervous system (CNS) diseases such as moyamoya disease, cerebral venous thrombosis, and Sturge-Weber syndrome was also described on susceptibility-weighted imaging (SWI), and the clinical implications of BS were discussed. The purpose of this review is to demonstrate BS on SWI in various CNS diseases and its mechanisms in the above-mentioned diseases.

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Cerebral amyloid angiopathy (CAA) is an age-related small vessel disease pathologically characterized by the progressive accumulation of amyloid-beta (Aβ) peptide in cerebrovascular walls, affecting both cortical and leptomeningeal vessels. Amyloid deposition results in fragile vessels, which may lead to lobar intracerebral hemorrhage (ICH) and cognitive impairment. To evaluate the probability and severity of CAA, the imaging markers depicted on CT and MRI techniques are crucial, as brain pathological examination is highly invasive.

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Aims: Photon-counting detector computed tomography (PCD-CT), which allows the exclusion of electronic noise, shows promise for significant dose reduction in coronary CT angiography (CCTA). This study aimed to assess the radiation dose and image quality of CCTA using PCD-CT, combined with high-pitch helical scanning and an ultra-low tube potential of 70 kVp, and investigate the effect of a sharp kernel on image quality and stenosis assessment in such an ultra-low-dose CCTA setting.

Methods And Results: Forty patients (65% male) with stable heart rates and no prior coronary interventions were included.

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Purpose: Risk stratification for incidence of major adverse cardiovascular events (MACE) in patients with dialysis-dependent end-stage renal disease (dd-ESRD) is challenging. Moreover, the usefulness of coronary CT angiography (CCTA) is often limited because of high calcification. This study aimed to investigate the prognostic value of comprehensive cardiac CT in patients with dd-ESRD for predicting MACE.

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Soluble B-cell maturation antigen (sBCMA) is overexpressed on multiple myeloma (MM) cells. We investigated whether sBCMA levels correlated with other myeloma tumor volume indicators and its utility in monitoring oligo-secretory/non-secretory (O-S/Non-S) MM. In 115 patients with newly diagnosed MM, sBCMA was compared with M-protein levels, bone marrow plasma cells (BMPCs), circulating tumor cells (CTCs), and total diffusion volume (tDV; estimated by whole-body diffusion-weighted magnetic resonance imaging) at diagnosis.

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Purpose: To investigate the effectiveness and safety of thoracic endovascular aortic repair (TEVAR) for infectious aortic diseases.

Materials And Methods: Patients who underwent TEVAR for infectious aortic diseases including infected thoracic aortic aneurysm, aortobronchial fistula (ABF), and aortoenteric fistula from December 2011 to October 2022 at 4 institutions were retrospectively studied. The primary outcome of the study was overall survival, whereas the secondary outcome was comprehensive adverse events.

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Objectives: This study aimed to investigate the relationship between microvascular status in the non-ischemic myocardium and the diagnostic performance of stress dynamic CT perfusion imaging (CTP) in detecting hemodynamically significant stenosis.

Materials And Methods: This study included 157 patients who underwent coronary computed tomography angiography (CTA), CTP, and invasive coronary angiography (ICA), including fractional flow reserve (FFR). Hemodynamically significant stenosis was defined by FFR and ICA.

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Purpose: To evaluate the value of Tc-99m-diethylenetriamine-penta-acetic acid-galactosyl human serum albumin (Tc-GSA) single photon emission computed tomography (SPECT) for assessing liver fibrosis, and to assess its complementary value to other liver function indices such as fibrosis-4 (FIB-4) index and indocyanine green (ICG) clearance test parameters (ICG-R15 and ICG-K).

Procedures: Seventy-eight patients with chronic liver disease and hepatocellular carcinoma who underwent Tc-GSA scintigraphy and other liver function tests including ICG test and FIB-4 index prior to hepatectomy were studied. Tc-GSA imaging was performed with SPECT/CT scanner (Discovery NM/CT 670).

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Article Synopsis
  • The study aimed to evaluate the effectiveness of two blind source separation techniques (SOBI and ICA) against principal component analysis (PCA) for identifying cardiac triggers in 5D whole-heart MRI.
  • Data was collected from three different groups: healthy volunteers, congenital heart disease patients, and patients with suspected coronary artery disease, each undergoing MRI scans with different protocols.
  • Results showed SOBI provides more accurate and sharper cardiac triggers compared to PCA and ICA, demonstrating its reliability across varying patient conditions and noise levels.
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This study aims to investigate the efficacy of thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD) complicated by malperfusion. This retrospective study included patients who underwent TEVAR for the treatment of TBAD complicated by malperfusion from June 1998 to June 2022 in four institutions. In addition to the common outcomes, including short- and medium-term mortality and morbidity, the preservation of each organ was investigated.

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The lung is a major dose-limiting organ for radiation therapy (RT) for cancer in the thoracic region, and the clarification of radiation-induced lung damage (RILD) is important. However, there have been few reports containing a detailed comparison of radiographic images with the pathological findings of radiation pneumonitis (RP)/radiation fibrosis (RF). We recently reported the upregulated expression of tenascin-C (TNC), an inflammation-associated extracellular matrix molecule, in surgically resected lung tissue, and elevated serum levels were elevated in a RILD patient.

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Background: Coronary artery disease (CAD) and coronary microvascular disease (CMD) are significant contributors to angina pectoris, necessitating reliable diagnostic techniques for effective management. While positron emission tomography has been the non-invasive gold standard for myocardial blood flow (MBF) quantification, stress dynamic CT myocardial perfusion imaging (CTMPI) has emerged as a promising alternative. This study aimed to evaluate the test-retest reproducibility of MBF measurements obtained using dynamic CTMPI.

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Objectives: Physician's evaluation of interstitial lung disease (ILD) extension with high-resolution computed tomography (HRCT) has limitations such as lack of objectivity and reproducibility. This study aimed to investigate the utility of computer-based deep-learning analysis using QZIP-ILD® software (DL-QZIP) compared with conventional approaches in connective tissue disease (CTD) -related ILD.

Methods: Patients with CTD-ILD visiting our Rheumatology Centre between December 2020 and April 2024 were recruited.

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Objective: To develop and validate a scoring system to predict mid-term adverse events after elective thoracic endovascular aortic repair (TEVAR).

Methods: In this multicenter retrospective observational cohort study, 350 patients who underwent elective TEVAR for thoracic aortic disease between January 2008 and December 2021 were analyzed. The primary outcome was the first adverse event occurring within 5 years of the initial TEVAR, which included death during the initial hospitalization, perioperative neurologic complication, stent graft-induced new entry, dissection, rupture, graft infection, and reintervention related to the initial TEVAR.

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To evaluate the usefulness of low-keV multiphasic computed tomography (CT) with deep learning image reconstruction (DLIR) in improving the delineation of pancreatic ductal adenocarcinoma (PDAC) compared to conventional hybrid iterative reconstruction (HIR). Thirty-five patients with PDAC who underwent multiphasic CT were retrospectively evaluated. Raw data were reconstructed with two energy levels (40 keV and 70 keV) of virtual monochromatic imaging (VMI) using HIR (ASiR-V50%) and DLIR (TrueFidelity-H).

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The effect of irradiation during computed tomography (CT) imaging on implantable cardioverter-defibrillators (ICDs) has not been fully evaluated in various settings. The purposes of this study were to evaluate the occurrence of electromagnetic interference (EMI) during CT irradiation in various clinically available ICDs with phantom experiments and to determine the potential risks related to irradiation during CT imaging. Five types of clinically available ICDs from five manufacturers were tested.

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Purpose: To evaluate the amide proton transfer (APT), tumor blood flow (TBF), and apparent diffusion coefficient (ADC) combined diagnostic value for differentiating intracranial malignant tumors (MTs) from benign tumors (BTs) in young patients, as defined by the 2021 World Health Organization classification of central nervous system tumors.

Methods: Fifteen patients with intracranial MTs and 10 patients with BTs aged 0-30 years underwent MRI with APT, pseudocontinuous arterial spin labeling (pCASL), and diffusion-weighted imaging. All tumors were evaluated through the use of histogram analysis and the Mann-Whitney U test to compare 10 parameters for each sequence between the groups.

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Article Synopsis
  • The study aimed to see if cardiovascular magnetic resonance radiomics can differentiate between noncollagen and inflammatory extracellular space from collagen in patients with dilated cardiomyopathy.
  • Researchers analyzed data from 132 patients who had undergone heart imaging and a biopsy, calculating various radiomic features and using principal component analysis to narrow them down for better diagnostic accuracy.
  • Results showed four distinct histopathological groups, revealing that noncollagenous extracellular space expansion had the strongest link to myocardial inflammation, and using radiomics improved the differentiation between types of extracellular space compared to traditional imaging methods.
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Objectives: Rheumatoid arthritis (RA) related interstitial lung disease (ILD) impacts on the treatment strategy and its prognosis in patients with RA. However, the relationship between RA disease activity and the severity of comorbid ILD has not been fully investigated. This study aimed to investigate the impact of RA disease activity on the severity of comorbid ILD in detail based on currently established visual scoring method along with physiological severity.

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Purpose: Predicting nonalcoholic fatty liver disease (NAFLD) following pancreaticoduodenectomy (PD) is challenging, which delays therapeutic intervention and makes its prevention difficult. We conducted this study to assess the potential application of preoperative computed tomography (CT) radiomics for predicting NAFLD.

Methods: The subjects of this retrospective study were 186 patients with PD from a single institution.

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