MR-Guided Biopsies of the Prostate in Supine Patient Position

Prompted by elevated PSA levels, more than a million men in the United States alone have to undergo transrectal ultrasound (TRUS)-guided prostate biopsy to clarify suspicion for prostate cancer per year [1]. Unlike pathways for other malignancies, biopsy of the prostate is performed by standardized, systematic but essentially random sampling [2]. The major limitation of this approach is that clinically insignificant cancers are often identified by chance while, even more important, clinically significant cancers may remain undetected [3, 4]. As a result of this uncertainty, more than one-third of men whose first biopsy was negative are rebiopsied within 5 years [1]. Over recent years, multiparametric magnetic resonance imaging (mpMRI), combining the morphological assessment of T2-weighted (T2w) imaging with different functional imaging techniques such as diffusion-weighted imaging (DWI) and dynamic contrast enhanced imaging (DCE) has become a mature tool for localizing and visualizing suspicious foci in the prostate.