Multi-reader evaluation of the prostate imaging quality score system version 2 (PI-QUAL V2) and its clinical application.

[OBJECTIVES] The objectives of this study were: (1) to investigate the consistency of PI-QUAL V2 and (2) to observe the impact of PI-QUAL V2 on the diagnostic performance for csPCa.

[METHODS] This retrospective study included 581 patients who underwent prostate MRI exams and had definitive pathological reports between January and December 2023. All histopathological specimens were evaluated, and an ISUP Grade Group ≥ 2 was considered as csPCa. Four radiologists independently assigned PI-QUAL V2 scores to each patient, with one of the readers re-scoring after a three-month interval. Cohen's and Fleiss' Kappa were used to determine inter-reader agreement, and the area under the receiver operating characteristic curve (AUC-ROC) was used to compare diagnostic performance. A p < 0.05 was considered statistically significant.

[RESULTS] The study comprised 581 individuals (median [IQR] age, 70 [66-75] years). The consistency was moderate for T2WI, DWI, and PI-QUAL V2, and substantial for DCE. For PI-RADS V2.1 categorization tasks, the proportion of PI-RADS 3 gradually decreased with improving image quality, and a statistical difference was found between PI-QUAL 1 and 3 (p < 0.001). However, regardless of whether PI-RADS ≥ 3 or ≥ 4 was used as the "suspicious for cancer" threshold, there was no significant difference in overall diagnostic performance for csPCa among different PI-QUAL V2 scores (AUC 0.741-0.844).

[CONCLUSION] PI-QUAL V2 plays a positive role in inter-reader reproducibility and radiologists' MRI diagnosis. Regarding the limited value of PI-QUAL V2 in the overall diagnosis of csPCa, further exploration with larger sample sizes and studies may be needed in the future.

[KEY POINTS] Question PI-QUAL V2 has overcome the limitations of V1, but its clinical application status remains uncertain. Findings PI-QUAL V2 exhibits a favorable impact on inter-reader reproducibility and radiologists' MRI diagnosis, albeit its overall impact on diagnosing clinically significant prostate cancer remains limited. Clinical relevance While simplifying the scoring system, PI-QUAL V2 retains high inter-reader agreement. A suboptimal PI-QUAL V2 score may undermine radiologists' confidence in image interpretation, resulting in a decreased detection rate of clinically significant prostate cancer.