Prostate Imaging Quality (PI-QUAL): A New Quality Control Scoring System for Multiparametric Magnetic Resonance Imaging of the Prostate from the PRECISION trial.

The PRECISION trial was a multicentre randomised study that demonstrated that multiparametric magnetic resonance imaging (mpMRI)-targeted biopsy is superior to standard transrectal ultrasound-guided biopsy for the detection of prostate cancer. The outcomes of studies reporting mpMRI-targeted biopsies are dependent on the quality of the mpMRI but there are currently no scoring systems available for evaluating this. We introduced a novel scoring system, the Prostate Imaging Quality (PI-QUAL) score, to assess the quality of scans in the PRECISION trial. PI-QUAL is a score on a Likert scale from 1 to 5, where 1 means that no mpMRI sequences are of diagnostic quality and 5 implies that each sequence is independently of optimal diagnostic quality. Fifty-eight out of 252 (23%) mpMRI scans chosen at random from each of the 22 centres in this trial were evaluated by two experienced radiologists from the coordinating trial centre, in consensus, blinded to pathology results. Overall, the mpMRI quality in the centres participating in PRECISION was good. MpMRI quality was of sufficient diagnostic quality (PI-QUAL ≥3) for 55 scans (95%) and of good or optimal diagnostic quality (PI-QUAL ≥4) for 35 scans (60%). Fifty-five out of 58 (95%) scans were of diagnostic quality for T2WI, followed by DWI (46/58 scans; 79%), and DCE (38/58 scans; 66%). Further validation of this scoring system is warranted. PATIENT SUMMARY: In this study we developed a scoring system (PI-QUAL) to assess the quality of multiparametric magnetic resonance imaging (mpMRI) in prostate cancer detection. We used scans from 22 centres that participated in the PRECISION trial. Although there was room for improvement in images that used intravenous contrast, we found that mpMRI in the PRECISION trial was of sufficient diagnostic quality (PI-QUAL score ≥3) for 95% of the scans.