Prostate Imaging and Data Reporting System Version 2 as a Radiology Performance Metric: An Analysis of 18 Abdominal Radiologists

Purpose: To determine expected trained provider performance dispersion in Prostate Imaging and Data Reporting System version 2 (PI-RADS v2) positive predictive values (PPVs).

Methods: This single-center quality assurance retrospective cohort study evaluated 5,556 consecutive prostate MRIs performed on 4,593 patients. Studies were prospectively interpreted from October 8, 2016, to July 31, 2020, by 18 subspecialty-trained abdominal radiologists (1-22 years' experience; median MRIs per radiologist: 232, first-to-third quartile range [Q1-Q3]: 128-440; 13 interpreted at least 30 MRIs with a reference standard). Maximum prospectively reported whole-gland PI-RADS v2 score was compared to post-MRI biopsy histopathology obtained within 2 years. The primary outcome was PPV of MRI by provider stratified by maximum whole-gland PI-RADS v2 score.

Results: Median provider-level PPVs for the radiologists who interpreted ≥30 MRIs with a reference standard were PI-RADS 3 (22.1%; Q1-Q3: 10.0%-28.6%), PI-RADS 4 (49.2%; Q1-Q3: 41.4%-50.0%), PI-RADS 5 (81.8%; Q1-Q3: 77.1%-84.4%). Overall, the maximum whole-gland PI-RADS v2 score was PI-RADS 1 to 2 (34.6% [1,925]), PI-RADS 3 (8.5% [474]), PI-RADS 4 (21.0% [1,166]), PI-RADS 5 (18.3% [1,018]), no PI-RADS score (17.5% [973]). System-level (all providers) PPVs for maximum PI-RADS v2 scores were 20.0% (95% confidence interval [CI]: 15.7%-24.9%) for PI-RADS 3, 48.5% (95% CI: 44.8%-52.2%) for PI-RADS 4, and 80.1% for PI-RADS 5 (95% CI: 75.7%-83.9%).

Conclusion: Subspecialty-trained abdominal radiologists with a wide range of experience can obtain consistent positive predictive values for PI-RADS v2 scores of 3 to 5. These data can be used for quality assurance benchmarking.