What Is Magnetic Resonance Imaging (MRI)?
Magnetic resonance imaging or an MRI is a noninvasive test that uses a powerful magnetic field, radio frequency pulses and a computer to produce a detailed image of the prostate and surrounding tissues. The detailed images produced by the MRI allows a physician to determine whether the cancer has spread beyond the prostate into the seminal vesicles or other nearby structures. The images can then be examined on a computer monitor, transmitted electronically, printed or copied to a removable medium like a usb drive or CD.
Why Would My Doctor Refer Me For This Procedure?
The primary reason a doctor might request an MRI of the prostate is for the evaluation of prostate cancer. The test is commonly used to evaluate the extent of prostate cancer in order to determine if the cancer is confined to the prostate, or if it has spread (metastasized) beyond the prostate gland.
MRI scans take relatively longer to complete than a CT scan – often taking up to an hour. You will be asked to change into a hospital gown and then lie on a table attached to the MRI machine. The table on which you will be lying on will then be moved into the MRI machine. The machine itself is a large box with a central tunnel. Certain MRI exams may require an injection of a dye (contrast material) which will help to identify certain anatomic structures on the scan images.
During the procedure you will have to lie as still as possible during the scan. To improve the accuracy of the MRI, a probe, called an endorectal coil, will be placed inside your rectum for the duration of the scan. If needed, a sedative can be administered intravenously to relieve any nervousness or anxiety while the scanned is being performed.
Benefits vs. Risks
As with any type of medical procedure there are inherent “pros & cons” related to having an MRI done. Some of these include:
- MRI is a noninvasive imaging technique that does not involve exposure to ionizing radiation.
- The contrast material used in some MRI exams is less likely to produce an allergic reaction than the iodine-based contrast materials.
- Although the strong magnetic field is not harmful in itself, implanted medical devices that contain metal may malfunction or cause problems during an MRI exam.
- If an endorectal coil is used during the scan, there is also a very small risk of damage to the rectum.