Multicenter analysis for inter reader agreement of PIQUAL score v2 for basic readers in prostate MRI

The Prostate Imaging Quality (PI-QUAL) V2 is a simplified update of PI-QUAL V1 for assessing image quality in multiparametric prostate MRI (mpMRI), aimed at improving clinical use and reproducibility. This study evaluated inter-reader agreement of PI-QUAL V2 among basic prostate readers using multicenter mpMRI data and compared it to PI-QUAL V1. Five readers assessed T2-weighted, DWI (including ADC maps), and DCE images from 274 men (median age: 71 years, IQR: 60-78) across five centers. Inter-reader agreement was measured using weighted Gwet's AC1 coefficients and compared using bootstrapped confidence intervals. For PI-QUAL V1, coefficients ranged from 0.659 to 0.855, indicating substantial-to-almost perfect agreement. For PI-QUAL V2, coefficients ranged from 0.821 to 0.897, showing almost perfect agreement. All 10 pairwise comparisons achieved almost perfect agreement for PI-QUAL V2, compared to only 3 of 10 for V1. Additionally, three comparisons showed non-overlapping confidence intervals, indicating statistically significant improvements with V2. PI-QUAL V2 demonstrated consistently higher inter-reader agreement than V1, with basic prostate readers achieving almost perfect agreement across multicenter mpMRI data. These findings highlight the improved reliability and clinical applicability of PI-QUAL V2.