LAUSR

INTRODUCTION To evaluate the performance of the Vesical Imaging-Reporting and Data System (VIRADS) in differentiating muscle-invasive and non-muscle-invasive bladder cancer and whether this reporting system improves inter-reader agreement. METHODS Sixty-four cases of multiparametric 3 tesla bladder MRI from January 2014 to May 2020 were reviewed retrospectively. T2-weighted, diffusion and post-contrast images were reviewed. All magnetic resonance images were reported by a radiologist with 15 years' experience (Reader 1) and a final year radiology trainee with a special interest in urogenital imaging with 3 years of experience (Reader 2). Both readers were blinded to clinical history and histopathology results when scoring each lesion. RESULTS The sensitivity and specificity for differentiating MIBC and NMIBC were 91% and 68%, respectively, for Reader 1 and 91% and 63%, respectively, for Reader 2. The inter-reader agreement for assigning VIRADS scores was 0.79. The area under the receiver operator curve for Reader 1 and 2 were not significantly different (Reader 1 = 0.79, Reader 2 = 0.77, P = 0.83). CONCLUSIONS Staging of bladder cancer prior to treatment can be accurately and reliably diagnosed using VIRADS, a novel, standardised reporting system for bladder MRI.