Bajgiran AM, et al. - Via a retrospective cohort study that included 218 men with 240 unilateral prostate cancer (PCa) lesions assessed by both 3-T multiparametric MRI and whole-mount histopathologic analysis, the researchers assessed performance of the apparent diffusion coefficient (ADC_ratio) ratio with that of conventional ADC to discover high-grade PCa vs low-grade PCa using whole-mount (WM) histopathologic analysis as a reference. A higher AUC value of ADC_{ratio_mean} for discriminating PCa lesions was noted. During the stratification by PCa zonal location, significantly more robust efficiency of the ADC_{ratio_mean} in the transition zone in comparison with the peripheral zone was observed. In both the endorectal coil and non–endorectal coil subcohorts, nonsignificant but better performance of the ADC_{ratio_mean}, especially in the former, was seen. Hence, the ADC ratio presented the best AUC value as an intrapatient-normalized diagnostic tool for differentiation of low-grade from high-grade PCa on 3-T MRI.