XXXX : Interobserver Agreement and Accuracy with the Revised Prostate Imaging Reporting and Data System at Multiparametric MR Imaging.

@entity1 @entity263
UNASSIGNED: Purpose To evaluate accuracy and interobserver variability with the use of the Prostate Imaging Reporting and Data System (PI-RADS) version 2.0 for detection of @entity263 at multiparametric magnetic resonance (MR) imaging in a biopsy-na  ve @entity1 population. Materials and Methods This retrospective HIPAA-compliant study was approved by the local ethics committee, and written informed consent was obtained from all @entity1 for use of their imaging and histopathologic data in future research studies. In 101 biopsy-na  ve @entity1 with elevated prostate-specific antigen levels who underwent multiparametric MR imaging of the prostate and subsequent transrectal ultrasonography (US)-MR imaging fusion-guided biopsy, suspicious lesions detected at multiparametric MR imaging were scored by five readers who were blinded to pathologic results by using to the newly revised PI-RADS and the scoring system developed in-house. Interobserver agreement was evaluated by using k statistics, and the correlation of pathologic results with each of the two scoring systems was evaluated by using the Kendall    correlation coefficient. Results Specimens of 162 lesions in 94 @entity1 were sampled by means of transrectal US-MR imaging fusion biopsy. Results for 87 (54%) lesions were positive for @entity263 . Kendall    values with the PI-RADS and the in-house-developed scoring system, respectively, at T2-weighted MR imaging in the peripheral zone were 0.51 and 0.17 and in the transitional zone, 0.45 and -0.11; at diffusion-weighted MR imaging, 0.42 and 0.28; at dynamic contrast material-enhanced MR imaging, 0.23 and 0.24, and overall suspicion scores were 0.42 and 0.49. Median k scores among all possible pairs of readers for PI-RADS and the in-house-developed scoring system, respectively, for T2-weighted MR images in the peripheral zone were 0.47 and 0.15; transitional zone, 0.37 and 0.07; diffusion-weighted MR imaging, 0.41 and 0.57; dynamic contrast-enhanced MR imaging, 0.48 and 0.41; and overall suspicion scores, 0.46 and 0.55. Conclusion Use of the revised PI-RADS provides moderately reproducible MR imaging scores for detection of clinically relevant disease. (  ) RSNA, 2015 Online supplemental material is available for this article.
