Vesical Imaging–Reporting and Data System for Multiparametric MRI to Predict the Presence of Muscle Invasion for Bladder Cancer

BACKGROUND: The Vesical Imaging-Reporting and Data System (VI-RADS) is a newly developed system of bladder cancer staging with multiparametric MRI (mpMRI), which can be used to predict the presence of muscle invasion for bladder cancer. PURPOSE: WI, diffusion-weighted imaging [DWI], and dynamic contrast-enhanced image [DCEI]) and VI-RADS for diagnosing the muscle invasive bladder cancer (MIBC). STUDY TYPE: Retrospective. POPULATION: In all, 66 pathologically proven bladder cancers in 32 patients. FIELD STRENGTH/SEQUENCE: WI, DWI, and DCEI. ASSESSMENT: WI, DWI, and DCEI using a five-point score system. Based on the scores in the three sequences, reviewers scored each bladder cancer with reference to VI-RADS categories. We evaluated the diagnostic performance of each of three mpMRI sequences and the final VI-RADS categorization for diagnosing MIBC. STATISTICAL TESTS: Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and the area under the curve (AUC) of each of three sequences separately and VI-RADS categorization for diagnosing the MIBC. RESULTS: The diagnostic performances of each of the three mpMRI series and VI-RADS for diagnosing MIBC were excellent. Especially using the optimal cutoff score >3 for predicting MIBC on DWI, DCEI, and VI-RADS, the sensitivity, specificity, PPV, NPV, and AUC values were 90% (95% confidence interval [CI]: 0.56, 1.00), 100% (95% CI: 0.94, 1.00), 100% (95% CI: 0.66. 1.00), 98.3% (95% CI: 0.91, 1.00), and 0.95, respectively. DATA CONCLUSION: mpMRI based on VI-RADS can stratify patients with bladder cancer according to the presence of muscle invasion. LEVEL OF EVIDENCE: 3. TECHNICAL EFFICACY STAGE: 2. J. Magn. Reson. Imaging 2020;52:1249-1256.