Magnetic Resonance Imaging of the Prostate
Prostate magnetic resonance (MR) provides high-resolution images of the prostate; seminal vesicles; and nearby pelvic organs and structures, including the bladder and rectum.
High-resolution T2-weighted imaging, diffusion-weighted imaging, MR spectroscopy, and dynamic contrast-enhanced T1-weighted imaging all have been shown to detect prostate cancer. A combination of all four techniques is used to maximize the sensitivity and specificity of the examination.
We perform the examination using only the highest field-strength magnets available in routine clinical use (3-tesla). Images are acquired both prior to and after IV administration of gadolinium contrast. An endorectal coil is used whenever possible to improve image quality. Prostate MR may be indicated for evaluation of patients with biopsy-proven or suspected prostate cancer. The primary uses and contraindications for prostate MR are described below.
Prostate MR is suitable for
- Identifying areas suspicious for carcinoma in order to direct transrectal ultrasound-guided biopsy in patients who have concerning PSA increases without documented prostate cancer.
- Detecting multifocal disease or disease spread in patients with biopsy-proven prostate cancer prior to considering focal therapy.
- Identifying extension of biopsy-proven prostate cancer outside the prostatic capsule and involvement of either the seminal vesicles or neurovascular bundle.
- Detecting lymphadenopathy or rectal or bladder invasion in patients with suspected or biopsy-proven prostate cancer.
- Assessing the possibility of recurrence after cryotherapy or prostatectomy.
- Recent biopsy of the prostate (within eight weeks), which can mask prostate cancer on MR. If possible, patients should not undergo prostate MR after a recent biopsy.
- Presence of pacemakers, defibrillators, or implanted ferromagnetic metallic foreign bodies. The presence of other implanted medical devices is evaluated on a case-by-case basis. Most modern urological prostheses are of no concern.
- Moderate-to-severe CKD (glomerular filtration rate less than 30 mL/min/1.73m2). Tailored non-contrast-enhanced studies can be performed on these patients.