Implementing PI-QUAL in Clinical Practice: A Systematic Review of Reproducibility, Diagnostic Impact, and the Role of Education and Automation.

INTRODUCTION: Variation in prostate MRI image quality persists despite established acquisition guidelines, highlighting the need for objective and reproducible methods of quality assessment. The Prostate Imaging Quality (PI-QUAL) score has been proposed to address this. This systematic review evaluates the inter-reader reproducibility of PI-QUAL scoring, its impact on prostate MRI interpretation, and factors influencing its implementation. METHODS: A systematic review was conducted in accordance with PRISMA guidelines, with searches of PubMed, Medline Ovid and Embase from inception to June 2026. Studies were included if PI-QUAL was evaluated as a primary or defined secondary outcome. Risk of bias was assessed using QUADAS-2. RESULTS: Thirty-one studies were included. Inter-reader agreement for PI-QUAL generally ranged from moderate to near-perfect among reader groups of similar background and experience, although methodological heterogeneity contributed to variability across studies. Structured education consistently improved PI-QUAL scoring performance and reduced variability between professional groups. Higher PI-QUAL scores were associated with improved sensitivity for clinically significant prostate cancer detection, fewer equivocal PI-RADS 3 assessments, and more reliable local tumour staging, whereas improvements in specificity, positive predictive value, and negative predictive value were less consistent. CONCLUSION: Current evidence supports broader implementation of PI-QUAL as a reproducible and clinically relevant quality assurance framework for prostate MRI. Its reproducibility across different reader groups and association with improved MRI interpretation support integration into routine prostate MRI practice, although prospective multicentre studies evaluating implementation strategies and patient-level clinical outcomes remain required.