An MR-guided biopsy, for example, prostate biopsy, is performed by a mechanical tool for stabilizing the patient in prone position and for guiding the biopsy needle into defined targeted lesions in the prostate gland. The patient can lay prone in the MRI. The apparatus can guide an MR-visible, sterile needle sleeve, which can have a hollow tube filled with contrast media, through the anus onto the inner wall of the colon. Due to the visibility of the contrast media in the sleeve, the apparatus can be guided to the exact position. The sleeve can incorporate a tube within the contrast media filled sleeve to insert the biopsy needle and to push this needle forward into the prostate. The apparatus can utilize various mechanical mechanisms to stereotactically move the needle or needle sleeve in various directions.