Comparison of Biparametric and Multiparametric MRI for Clinically Significant Prostate Cancer Detection With PI‐RADS Version 2.1

Background Biparametric MRI (bpMRI) without dynamic contrast‐enhanced MRI (DCE‐MRI) results in an elimination of adverse events, shortened examination time, and reduced costs, compared to multiparametric MRI (mpMRI). The ability of bpMRI to detect clinically significant prostate cancer (csPC) with the Prostate Imaging and Reporting Data System version 2.1 (PI‐RADS v2.1) compared to standard mpMRI has not been studied extensively. Purpose To compare the interobserver reliability and diagnostic performance for detecting csPC of bpMRI and mpMRI using PI‐RADS v2.1. Study Type Retrospective. Population In all, 103 patients with elevated prostate‐specific antigen (PSA) levels who underwent mpMRI and subsequent MRI‐ultrasonography fusion‐guided prostate‐targeted biopsy (MRGB) with or without prostatectomy. Field Strength/Sequences T2‐weighted imaging (T2WI), diffusion‐weighted imaging (DWI), and DCE‐MRI at 3T. Assessment Three readers independently assessed each suspected PC lesion, assigning a score of 1–5 for T2WI, a score of 1–5 for DWI, and positive and negative for DCE‐MRI according to PI‐RADS v2.1 and determined the overall PI‐RADS assessment category of bpMRI (T2WI and DWI) and mpMRI (T2WI, DWI, and DCE‐MRI). The reference standard was MRGB or prostatectomy‐derived histopathology. Statistical Testing Statistical analysis was performed using the kappa statistic and McNemar and Delong tests. Results Of the 165 suspected PC lesions in 103 patients, 81 were diagnosed with csPC and 84 with benign conditions. Interobserver variability of PI‐RADS assessment category showed good agreement for bpMRI (kappa value = 0.642) and mpMRI (kappa value = 0.644). For three readers, the diagnostic sensitivity was significantly higher for mpMRI than for bpMRI (P