Value of bowel preparation techniques for prostate MRI: a preliminary study.

Background: Bowel preparation before multiparametric MRI (mpMRI) of the prostate is performed widely, despite contradictory or no evidence for efficacy.

Purpose: To investigate the value of hyoscine N-butylbromide (HBB), microenema (ME) and 'dietary restrictions' (DR) for artifact reduction and image quality (IQ) in mpMRI of the prostate.

Study Type: Retrospective.

Population: Between 10/2018 and 02/2020 treatment-naïve men (median age, 64.9; range 39.8-87.3) who underwent mpMRI of the prostate were included. The total patient sample comprised of n = 180 patients, who received either HBB, ME, were instructed to adhere to DR, or received a combination of those measures prior to the MR scan.

Field Strength/sequence: T2-weighted imaging (T2w), diffusion-weighted imaging (DWI), and dynamic contrast-enhanced MRI (DCE-MRI) scanned on two 3T systems.

Assessment: A radiologist specialized in urogenital imaging (R1) and a senior radiology resident (R2) visually assessed IQ parameters on transversal T2w, DWI and ADC maps on a 5-point Likert-like scale.

Statistical Tests: Group comparison between IQ parameters was performed on reader level using Kruskal-Wallis and Mann-Whitney U tests. Binary univariate logistic regression analysis was used to assess independent predictors of IQ. Interrater agreement was assessed using Intraclass Correlation Coefficient (ICC).

Results: 'DWI geometric distortion' was significantly more pronounced in the HBB+/ME-/DR- (R1, 3.6 and R2, 4.0) as compared to the HBB-/ME+/DR- (R1, 4.2 and R2, 4.6) and HBB+/ME+/DR- (R1, 4.3 and R2, 4.7) cohort, respectively. Parameters 'DWI IQ' and 'Whole MRI IQ' were rated similarly by both readers. ME was a significant independent predictor of 'good IQ' for the whole MRI for R1 [b = 1.09, OR 2.98 (95% CI 1.29, 6.87)] and R2 [b = 1.01, OR 2.73 (95% CI 1.24, 6.04)], respectively.

Data Conclusion: ME seems to significantly improve image quality of DWI and the whole mpMRI image set of the prostate. HBB and DR did not have any benefit.