Intra- and Interimage Reliability of Inter-Rectus Distance Measurements Determined via Ultrasound Imaging by the Same or Different Testers in Women in the Early Postpartum Period.

OBJECTIVES: No consensus regarding the optimal position and location for the measurement of the inter-rectus distance (IRD) via ultrasound (US) has been reached. By investigating the intra- and interimage reliability of IRD measurements taken in different positions and at different locations within and between testers, this study provides a theoretical basis for the current situation. METHODS: The IRD was measured via US in 46 women at 42-60 days after delivery at the superior margin of the umbilicus and 3 cm above, 5 cm above and 3 cm below the umbilicus while the women were in the supine, crunch and standing positions. In the interimage test, every participant was tested 2 times by Physician X and 1 time by Physician Y; in the intraimage test, the images collected by Physician X during the first test were saved in the machines, and two measurements were performed by Physician X and one measurement was performed by Physician Y. Paired t tests and intraclass correlation coefficients (ICCs) were calculated. RESULTS: Only the first IRD measurements by tester X and tester Y at 3 cm below the umbilicus in the crunch position were significantly different (9.56 ± 6.00 versus 11.00 ± 5.55) (P < .05). All the ICCs were greater than .75, and the intratester ICCs were greater than or equal to the corresponding intertester ICCs. The ICCs at 3 cm below the umbilicus were the smallest in the supine and crunch positions and the largest in the standing position due to the increased frequency of IRD values of 0. The ICCs for the crunch position were greatest according to the intraimage test but smallest according to the interimage test. The interimage ICCs between the two testers in the supine position at the superior margin, 3 cm above, 5 cm above, and 3 cm below the umbilicus were .972, .974, .975, and .956, respectively. CONCLUSIONS: Ultrasound imaging (USI) is a reliable method for measuring the IRD in women in the early postpartum period. The dynamic measurement of the IRD at or above the umbilicus in the supine position by different testers in real time showed the highest reliability.

Prostate Cancer Differentiation and Aggressiveness: Assessment With a Radiomic-Based Model vs. PI-RADS v2.

BACKGROUND: Multiparametric MRI (mp-MRI) combined with machine-aided approaches have shown high accuracy and sensitivity in prostate cancer (PCa) diagnosis. However, radiomics-based analysis has not been thoroughly compared with Prostate Imaging and Reporting and Data System version 2 (PI-RADS v2) scores. PURPOSE: To develop and validate a radiomics-based model for differentiating PCa and assessing its aggressiveness compared with PI-RADS v2 scores. STUDY TYPE: Retrospective. POPULATION: In all, 182 patients with biopsy-proven PCa and 199 patients with a biopsy-proven absence of cancer were enrolled in our study. FIELD STRENGTH/SEQUENCE: Conventional and diffusion-weighted MR images (b values = 0, 1000 sec/mm2 ) were acquired on a 3.0T MR scanner. ASSESSMENT: A total of 396 features and 385 features were extracted from apparent diffusion coefficient (ADC) images and T2 WI, respectively. A predictive model was constructed for differentiating PCa from non-PCa and high-grade from low-grade PCa. The diagnostic performance of each radiomics-based model was compared with that of the PI-RADS v2 scores. STATISTICAL TESTS: A radiomics-based predictive model was constructed by logistic regression analysis. 70% of the patients were assigned to the training group, and the remaining were assigned to the validation group. The diagnostic efficacy was analyzed with receiver operating characteristic (ROC) in both the training and validation groups. RESULTS: For PCa versus non-PCa, the validation model had an area under the ROC curve (AUC) of 0.985, 0.982, and 0.999 with T2 WI, ADC, and T2 WI&ADC features, respectively. For low-grade versus high-grade PCa, the validation model had an AUC of 0.865, 0.888, and 0.93 with T2 WI, ADC, and T2 WI&ADC features, respectively. PI-RADS v2 had an AUC of 0.867 in differentiating PCa from non-PCa and an AUC of 0.763 in differentiating high-grade from low-grade PCa. DATA CONCLUSION: Both the T2 WI- and ADC-based radiomics models showed high diagnostic efficacy and outperformed the PI-RADS v2 scores in distinguishing cancerous vs. noncancerous prostate tissue and high-grade vs. low-grade PCa. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:875-884.