PI-RADS

Turkbey B, Rosenkrantz AB, Haider MA, et al. Prostate Imaging Reporting and Data System Version 2.1: 2019 Update of Prostate Imaging Reporting and Data System Version 2. Defines the 1–5 assessment categories used here for a prostate lesion on multiparametric MRI, and the sequence-weighting rules (T2W, DWI/ADC, DCE) a radiologist uses to assign one.

Oerther B, Engel H, Bamberg F, Sigle A, Gratzke C, Benndorf M. Cancer detection rates of the PI-RADSv2.1 assessment categories: systematic review and meta-analysis on lesion level and patient level. Source of the patient-level cancer detection rates shown here (categories 1–5); pooled across 17 studies, with wide confidence intervals at the extremes.

PI-RADS v2.1 does not itself recommend a management step for a given category — that depends on PSA, PSA density, family history, prior biopsy, and local practice as well as the MRI. Biopsy is generally considered for category 4 or 5; for category 3, whether to biopsy depends on those other factors rather than the category alone; category 1 or 2 does not usually prompt biopsy on MRI grounds. The detection rate shown is for cancer generally, not specifically the clinically significant disease PI-RADS is designed to flag.