The purpose of this study was to demonstrate the use of a transrectal system that enables precise magnetic resonance (MR) image guidance, monitoring of prostate interventions The system used a closed-bore 1 5-T MR imaging unit, enables one to take advantage of the higher signal-to-noise ratio achieved with traditional magnet designs, which is crucial for accurate targeting, monitoring of prostate interventions In the first of the four canine studies, reliable needle placement, with all needles placed within 2 mm of the desired target site, was achieved In two other studies, MR imaging was used to monitor distribution of injected contrast agent solution (gadopentetate dimeglumine mixed with trypan blue dye) in, around the prostate, thereby confirming that solution had been delivered to the desired tissue, also detecting faulty injections In the final study, accurate placement, MR imaging of brachytherapy seeds in the prostate were demonstrated The described system provides a flexible platform for a variety of minimally invasive MR image-guided therapeutic, diagnostic prostate interventions