Pitfalls of Prostate Imaging Reporting and Data System Version 2: a Pictorial Essay

Prostate cancer is a significant health concern in men that is typically investigated by using serum prostate specific antigen and systematic transrectal ultrasound-guided prostate biopsy. Recently, two large prospective multicentre studies have demonstrated that using multiparametric magnetic resonance imaging to triage men with high serum prostate specific antigen levels was a more cost-effective strategy for diagnosing clinically significant cancer, compared with the traditional management pathway. The Prostate Imaging Reporting and Data System (PI-RADS), currently in its second version, was developed to provide technical guidelines on image acquisition and a structured system for reporting of multiparametric magnetic resonance imaging examinations. In this pictorial essay, we will provide an overview of the general technical considerations and guidelines on image interpretation and reporting using PI-RADS version 2, before illustrating the common pitfalls radiologists encounter when applying this system.