Bajgiran AM, et al. - Via a retrospective cohort study that involved 218 men with 240 unilateral PCa lesions evaluated by both 3-T multiparametric MRI and whole-mount histopathologic analysis, researchers assessed the performance of the apparent diffusion coefficient ratio (ADC_ratio; the ADC of the suspected prostate cancer [PCa] focus on MRI divided by the ADC in a noncancerous reference area) with that of conventional ADC for detection of high-grade PCa (Gleason score [GS] ≥ 3 + 4) vs low-grade PCa (GS = 3 + 3) with whole-mount (WM) histopathologic analysis used as a reference. A greater AUC value for discriminating PCa lesions with a GS of 3 + 3 was noted in the ADC_{ratio_mean} than those with a GS of 3 + 4 or greater. The ADC_{ratio_mean} had significantly more robust exactitude in the transition zone in comparison with the peripheral zone when stratified by PCa zonal location. When investigated based on endorectal coil use, in both the endorectal coil and non–endorectal coil subcohorts, the ADC_{ratio_mean} performed nonsignificantly better, however, it performed better in the former. Thus, for discrimination of low-grade from high-grade PCa on 3-T MRI, the ADC ratio gave the best AUC value as an intrapatient-normalized diagnostic tool.