PI-RADS is designed to improve focal lesion detection, localization, characterization, and risk stratification in patients with suspected cancer and consists of technical recommendation for MRI acquisition and a scoring system for image interpretation. PI-RADS uses a scale of 1–5 to report the overall probability of clinically significant prostate cancer on multiparametric MRI (mpMRI). The use of PI-RADS is limited to treatment naive patients and it should not be used for staging, assessment of treatment outcome, recurrence, or progression during surveillance.
The rationale for screening is that early detection and treatment of asymptomatic cancers could extend life, as compared with treatment at the time of clinical diagnosis. The introduction of prostate-specific antigen (PSA) testing has nearly doubled the lifetime risk of receiving a diagnosis of prostate cancer.
The Tumor-Node-Metastasis (TNM) System