太田 丞二

Introduction: Extracellular volume (ECV) analysis using computed tomography is recognized as a potential method for diagnostic application. It is currently the only noninvasive method for quantitatively evaluating myocardial fibrosis in dialysis patients for whom gadolinium contrast agents are contraindicated. In this study, we assessed the utility of ECV measurement via CT in the left ventricular (LV) myocardium (LVM) to predict major adverse cardiac events (MACEs) in dialysis patients. Materials and methods: We analyzed 57 dialysis patients who underwent cardiac CT and assessed the utility of LVM ECV (LV-ECV) for predicting MACEs. All the patients were followed for a median of 11 months, and MACEs occurred in 15 cases (26%). Results: LV-ECV and plasma brain natriuretic peptide levels were higher in subjects with MACEs than those without (40.29 ± 8.23% vs. 33.76 ± 4.60% and 1481 ± 997 vs. 807 ± 1109 pg/mL; both p < 0.05). Significant valvular disease was more frequently detected in patients with MACEs than those without (60% vs. 24%; p = 0.023). Serum hematocrit levels were significantly lower in patients with MACEs than those without (29 ± 5 vs. 34 ± 5; p < 0.001). The administration of statin was significantly lower in patients with MACEs than in those without (13% vs. 48%; p = 0.029). A receiver operating characteristic (ROC) curve analysis was performed using LV-ECV for predicting MACEs. The area under the curve was 0.80, and the best cut-off value of LV-ECV was 37.26% (p = 0.0003). In a Cox proportional hazards model, LV-ECV ≥ 37.26% was the only significant independent predictor of MACEs (p = 0.020). Conclusions: LV-ECV measured using CT is a useful predictor of MACEs in dialysis patients.

OBJECTIVE: Cardiac computed tomography (CT) helps screen coronary artery stenosis in cases with dilated cardiomyopathy (DCM). Extracellular volume fraction (ECV) analysis has recently been eligible for CT. METHOD: We evaluated the impact of ECV on the CT to predict the prognosis in DCM patients with heart failure with reduced ejection fraction (HFrEF). PATIENTS OR MATERIALS: We analyzed 101 consecutive DCM cases with HFrEF who underwent cardiac CT. All the patients had a lower left ventricular (LV) ejection fraction (LVEF) of less than 40%. We evaluated the effect of ECV to predict the patients' prognosis. Cardiovascular death, hospitalization due to heart failure, and fatal arrhythmic events were included in the major adverse cardiac events (MACE). RESULTS: MACE occurred in 27 cases (27%). The patients with MACE (27 cases) had an increased ECV on the LVM on the CT (37.2 ± 6.7 vs. 32.2 ± 3.6%, p = 0.0008) compared to the others (74 cases). Based on the receiver operating characteristics curve analysis, the best cutoff value of the ECV on the LVM to predict the MACE was 32.3%. The patients with ECV ≥ 32.3% had significantly higher MACE based on the Kaplan-Meier analysis. The ECV on the LVM was a significant marker to predict MACE based on the univariate Cox proportional hazard model (hazard ratio of 8.00, 95% confidence interval 1.88-33.97, p = 0.0048). CONCLUSIONS: ECV by CT is helpful to predict MACE in cases with DCM and HFrEF.

PURPOSE: Identification of the Adamkiewicz artery before aortic surgery is important for preventing postoperative complications due to spinal cord ischemia. The Adamkiewicz artery is difficult to identify due to its small diameter. Nitroglycerin has a vasodilatory effect and is used clinically to improve visualization of blood vessels on coronary computed tomography (CT) angiography. We investigated whether the vasodilatory effect of nitroglycerin could improve the ability to visualize the Adamkiewicz artery. METHODS: We extracted 33 cases wherein contrast-enhanced CT images were taken before and after aortic aneurysm surgery. Nitroglycerin was administered for coronary artery evaluation on the preoperative CT. However, no nitroglycerin was administered before the postoperative CT. Aortic contrast-to-noise ratio, CT value, image noise, and diameter of the Adamkiewicz artery and anterior spinal artery were measured. The depiction of the Adamkiewicz artery was graded into four grades and evaluated. These measurements were performed by two independent reviewers. RESULTS: In nitroglycerin-administered cases, the contrast-to-noise ratio and CT values were significantly higher (P < 0.001, P < 0.001, respectively); the Adamkiewicz artery and anterior spinal artery diameters were dilated (P = 0.005, P = 0.001, respectively). The Adamkiewicz artery score also improved significantly (P < 0.001). No significant difference was found in image noise. CONCLUSION: Nitroglycerin contributed to improving the Adamkiewicz artery's visualization.

INTRODUCTION: To date, there is limited evidence on the effects of bronchodilators on respiratory dynamics in chronic obstructive pulmonary disease (COPD). Dynamic chest radiography (DCR) is a novel radiographic modality that provides real-time, objective and quantifiable kinetic data, including changes in the lung area (Rs), tracheal diameter, diaphragmatic kinetics and pulmonary ventilation during respiration, at a lower radiation dose than that used by fluoroscopic or CT imaging. However, the therapeutic effect of dual bronchodilators on respiratory kinetics, such as chest wall dynamics and respiratory muscle function, has not yet been prospectively evaluated using DCR. AIM: This study aims to evaluate the effects of bronchodilator therapy on respiratory kinetics in patients with COPD using DCR. METHODS AND ANALYSIS: This is an open-label, prospective, single-centre, non-controlled, comparative study. A total of 35 patients with COPD, aged 40-85 years, with a forced expiratory volume in the first second of 30-80%, will be enrolled. After a 2-4 weeks washout period, patients will receive tiotropium/olodaterol therapy for 6 weeks. Treatment effects will be evaluated based on DCR findings, pulmonary function test results and patient-related outcomes obtained before and after treatment. The primary endpoint is the change in Rs after therapy. The secondary endpoints include differences in other DCR parameters (diaphragmatic kinetics, tracheal diameter change and maximum pixel value change rate), pulmonary function test results and patient-related outcomes between pre-therapy and post-therapy values. All adverse events will be reported. ETHICS AND DISSEMINATION: Ethical approval for this study was obtained from the Ethics Committee of Chiba University Hospital. The results of this trial will be published in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: jRCTs032210543.

PURPOSE: To identify the countermeasures and current status of disaster power outages in the radiology departments of hospitals. METHODS: A web-based questionnaire survey of 600 hospitals nationwide was conducted. The questionnaire survey covered 34 items, including availability of power in the radiology department in the event of a disaster and the impact of power outages on medical equipment in the radiology department. RESULTS: In all, 242 facilities (40.3%) responded to our survey. During power outages, 55.8%-68.2% of facilities were able to use CT, digital radiography, and angiography systems with their private generators. In 28.1%-40.7% of facilities, medical information systems were not available in all laboratories. In addition, power outages caused equipment malfunctions in 81.4% of facilities' radiology departments. CONCLUSION: We have identified the power supplied by private generators to the radiology department's medical equipment and medical information systems. Many medical equipment have malfunctioned due to power outages. Therefore, drills should be conducted to simulate various situations caused by power outages.