Prostate MRI quality assessment using PI-QUAL version 2: Comparative analysis between 1.5 T and 3 T scanners and its...

To assess prostate MRI image quality using Prostate Imaging Quality (PI-QUAL) version 2, to compare quality distributions between 1.5 T and 3 T MRI scanners, and to evaluate the association between image quality and concordance of MRI-based and pathological T-staging.

This retrospective study included 416 patients who underwent preoperative prostate MRI followed by radical prostatectomy between December 2021 and August 2024. MRI examinations were performed using one 1.5 T scanner and two 3 T scanners. Image quality was independently evaluated by two radiologists using PI-QUAL v2. MRI-based T-staging (mrT2, mrT3a, or mrT3b) was determined by consensus and compared with pathological T-staging. Differences in PI-QUAL scores were analyzed across scanners, and the association between PI-QUAL score and T-stage mismatch was evaluated using logistic regression. Inter-observer agreement was assessed using percent agreement and Gwet's agreement coefficients.

The proportion of examinations with acceptable image quality (PI-QUAL v2 ≥ 2) was significantly higher in 3 T group than in 1.5 T group (85.8% vs. 75.2%, p = 0.004). Among the three MRI scanners, the proportion of examinations with acceptable image quality differed significantly across scanners, with the highest proportion observed in MR2 (1.5 T: 75.2%, MR1: 82.6%, MR2: 89.1%; p = 0.026). PI-QUAL scores were significantly higher in cases with concordant MRI-based and pathological T-staging than in mismatched cases (p = 0.010). Higher PI-QUAL scores were independently associated with improved T-staging agreement (odds ratio, 1.59; 95% confidence interval, 1.17-2.16; p = 0.003), particularly in the 3 T subgroup. Inter-observer agreement for PI-QUAL v2 parameters was generally substantial to almost perfect, with variability observed for diffusion-weighted imaging parameters.

Higher prostate MRI image quality, as assessed by PI-QUAL v2, is significantly associated with improved concordance between MRI-based and pathological T-staging. These findings support the clinical relevance of standardized image quality assessment and highlight the role of PI-QUAL v2 as a practical quality assurance tool in prostate MRI.