Correlation of apparent diffusion coefficient ratio on 3.0 T MRI with prostate cancer Gleason score.

•ADCratio is a reliable and reproducible tool in quantification of diffusion restriction for clinically significant PCa foci.•Comparing an experienced and a new MRI reader, Inter-reader reliability in the calculation of ADCratio was excellent.•ADCratio has potential to replace the current practice of visual analysis of ADCtumour reduction, and provide an objective tool.