Figure 6:

Images in a 59-year-old man with a prostate-specific antigen level of 2.9 ng/mL and a prior negative prostate biopsy. (A) Axial T2-weighted MRI scan shows a subtle, noncircumscribed, moderately hypointense focus in the left base posteromedial peripheral zone (arrow) (T2-weighted MRI Prostate Imaging Reporting and Data System [PI-RADS] score of 3). On the (B) axial diffusion-weighted image with a high b value (1400 sec/mm²), the lesion has ill-defined mildly hyperintense signal (arrow), and on the (C) apparent diffusion coefficient (ADC) map, it has markedly hypointense signal (arrow) (diffusion-weighted imaging and ADC PI-RADS score of 3). On the (D) dynamic contrast-enhanced (DCE) MRI scan, the lesion shows early contrast enhancement (arrow) (DCE MRI PI-RADS score of positive). The final assessment category assigned was PI-RADS category 4. The focal abnormality was not identified at the time of the MRI interpretation by a novice reader, who assigned PI-RADS category 2 to the examination. Upon review of the images by a more experienced reader, the lesion was identified, and an MRI-targeted biopsy of the lesion revealed prostate cancer with a Gleason score of 3+4.