Yoshiyuki Ozawa

PURPOSE: In contrast to diffusion-weighted imaging (DWI) and dynamic contrast-enhanced perfusion MRI, different information from chemical exchange saturation transfer (CEST) imaging has been suggested to have potential for diagnosis of prostate cancer. The purpose of this study was to compare the descriptor capability for differentiating malignant from benign prostatic areas among three-dimensional (3D) amide proton transfer weighted (APTw) imaging using a newly developed 3D CEST sequence, DWI, and the combined descriptor method. MATERIALS AND METHODS: Fifty-two prostate cancer patients underwent DWI and 3D APTw imaging, surgical treatments, and pathological examinations. Then, 154 areas were identified as malignant, and 154 out of 624 areas were computationally selected as benign. From 3D APTw imaging and DWI, magnetization transfer ratio asymmetry (MTRasym) in the 3.5 ppm map and apparent diffusion coefficient (ADC) within malignant and benign prostatic areas were determined by ROI measurements. Then, a logistic regression analysis was conducted to evaluate the descriptors. An ROC analysis and McNemar's test were conducted to compare the diagnostic performance of MTRasym, ADC, and the combined discriminator method. RESULTS: The logistic regression analysis identified MTRasym (unit odds ratio: 3.6, p < 0.0001) and ADC (unit odds ratio: 0.03, p < 0.0001) as significant descriptors. The area under the curve (AUC) of the combined descriptor method (AUC = 0.86) was significantly larger than that of MTRasym (AUC = 0.81, p = 0.001) and ADC (AUC = 0.76, p < 0.0001). CONCLUSION: 3D APTw imaging is considered at least as valuable as DWI to distinguish malignant from benign prostatic areas. Combined descriptors could improve diagnostic performance, relative to each sequence alone.

Asthma, chronic rhinosinusitis with nasal polyps (CRSwNP), and eosinophilic otitis media (EOM) share type 2 inflammatory pathways. Although type 2-targeted biologic therapies have shown efficacy for these diseases, some patients exhibit dissociated responses to a single biologic. A case of severe asthma with CRSwNP and EOM that showed dissociated responses to biologic therapies and was successfully managed by biologic switching is reported. A 55-year-old man with asthma, recurrent CRSwNP requiring multiple surgeries and oral corticosteroid-dependent EOM was referred to our hospital. Nineteen months after starting dupilumab, EOM and endoscopic and radiological findings of CRSwNP improved partially. However, his nasal symptoms and olfactory dysfunction persisted, and asthma remained uncontrolled. After switching from dupilumab to mepolizumab, asthma control, nasal symptoms and olfactory dysfunction improved, and EOM remained well controlled. Careful monitoring of disease activity and consideration of biologic switching may help achieve optimal control in patients with type 2 united airway diseases.

PURPOSE: Since the clinical application of computed tomography (CT), cardiac and respiratory motion artifacts have caused decreased image quality and reduced detection or quantitative or qualitative evaluation of lung parenchymal or vascular abnormalities on chest CT with lung window settings in patients with pulmonary diseases. Recently, a deep learning (DL)-based motion correction algorithm (CLEAR Motion) has been developed and clinically used for chest CT. We hypothesized that CLEAR Motion can significantly reduce motion artifacts on chest CT examinations relative to conventional chest CT images reconstructed without CLEAR Motion. The purpose of this study was to determine the utility of CLEAR Motion for image quality improvement in chest CT with lung window settings in patients with various pulmonary diseases. MATERIALS AND METHODS: Fifty-six consecutive patients with various thoracic diseases underwent non-electrocardiogram-gated chest helical CT examination using a 320-detector row CT and underwent reconstruction using the conventional reconstruction method and CLEAR Motion. To compare the quantitative image quality, the cardio-pulmonary edge distance (CPED) and slope (CPES) were measured on each CT scan in the axial plane. Comparing cardiac motion reduction capability, overall image quality, cardiac motion artifact, and region conspicuity were visually assessed in the lung window setting on the axial, coronal, and sagittal planes. The paired t-test and Wilcoxon signed-rank test were then performed. RESULTS: The CPEDs and CPESs of the entire lung and left lung on CT with CLEAR Motion were significantly superior to those of CT without CLEAR Motion (p < 0.001). The overall image quality, cardiac motion artifact, and region conspicuity on CT with CLEAR Motion were significantly higher than those without CLEAR Motion on each plane (p < 0.001). CONCLUSION: The DL-based motion correction algorithm named as 'CLEAR Motion' has a potential to improve image quality on chest CT with lung window setting in patients with pulmonary diseases.

PURPOSE: To evaluate whether reverse encoding distortion correction (RDC) improves image quality and maintains apparent diffusion coefficient (ADC) measurements in diffusion-weighted imaging (DWI) on female pelvic MRI using a 1.5-T in in vitro and in vivo studies. METHODS: This retrospective, institutional review board-approved study included both in vitro and in vivo analyses of 31 women (mean age, 41 ± 15 years; range, 24-80 years) who underwent pelvic MRI between January and March 2022. T2-weighted image (T2WI) and DWI with and without RDC were acquired, and ADC maps were generated. Quantitative metrics included SNR, contrast-to-noise ratio (CNR), ADC values, and deformation ratio (DR), defined as the proportional area discrepancy between DWI and T2WI for the uterine corpus, cervix, ovary, and lesions. Qualitative assessments-overall image quality (OIQ), deformation severity (DS), and diagnostic confidence level (DCL)-were independently scored by 2 blinded radiologists using 5-point scales. RESULTS: In vitro SNR and ADC values showed no significant differences between DWI with and without RDC, with strong correlations to reference measurements (ρ = 0.99, P < 0.001). In vivo, SNR, CNR, and ADC values of the myometrium, cervix, and ovary did not differ significantly between 2 methods (P > 0.05). DRs were significantly lower in DWI with RDC than in DWI without RDC (P ≤ 0.0003). ADC values showed strong correlations between DWI with and without RDC on uterine corpus, cervix, ovary and lesions (ρ = 0.82-0.90, P < 0.001). Qualitative scores improved with RDC: higher OIQ (P = 0.0004), lower DS (P = 0.0004), and higher DCL (P = 0.03). Interobserver agreement ranged from substantial to almost perfect (κ = 0.78-0.97). CONCLUSION: RDC improves image quality and reduces image distortion in DWI on female pelvic MRI at a 1.5-T, while maintaining ADC measurements in in vitro and in vivo settings.

BACKGROUND: Prognostic markers reflecting nutritional vulnerability in idiopathic pulmonary fibrosis (IPF) remain poorly defined. METHODS: In this prospective cohort study, 63 stable outpatients with IPF were followed for 3 years. Sarcopenia was defined according to the 2019 Asian Working Group for Sarcopenia criteria. Serum transthyretin levels were measured concurrently. Cox proportional hazards regression, binary logistic regression, and Kaplan-Meier survival analyses were performed. RESULTS: During follow-up, 18 patients (29%) died and 21 (33%) experienced respiratory-related hospitalization. Serum transthyretin was an independent predictor of both 3-year mortality and respiratory-related hospitalization, even after adjusting for the Gender-Age-Physiology index. Conversely, sarcopenia and low appendicular skeletal muscle mass index (ASMI) were not independently associated with either outcome. Kaplan-Meier analysis demonstrated significant differences in both mortality and hospitalization according to serum transthyretin levels. Low ASMI evaluated using sex-specific cutoffs was associated with higher mortality in the unadjusted analysis, but not with hospitalization; sarcopenia was not significantly associated with either endpoint. CONCLUSIONS: Serum transthyretin may serve as a practical biomarker of nutritional vulnerability, providing complementary prognostic information beyond muscle mass-based assessment in IPF.