Men who require prostate biopsy will be approached and consented to enter this study. Participants will all undergo pre-biopsy mp-MRI and mp-USS of the prostate. Only men with positive scans will undergo prostate biopsy. The order in which lesions discovered on mp-MRI or on mp-USS are sampled will be randomised. All biopsies will be taken via the transperineal route in a single procedure. Comparison will be drawn between biopsy results of lesions detected by mp-USS with those lesions detected by mp-MRI. Consideration will be given as to whether a lesion detected by one imaging modality is the same abnormality as one detected by the other imaging modality, in the same patient. Analysis will be carried out at both the level of the lesion and the whole prostate. Men without suspicious lesions on either imaging modality will not proceed to biopsy.