An MRI, which stands for magnetic resonance imaging, is a type of noninvasive test that uses magnets and radio waves to create images of the inside of the body. Unlike a CT scan, an MRI uses no radiation and is considered a safer alternative.
The magnets and radio waves create cross-sectional images of the abdomen, which allow doctors to check for abnormalities in the tissues and organs without making an incision.
The technology used in an MRI allows doctors to examine the soft tissues without bones obstructing the view.
Your doctor may order an abdominal MRI scan if he or she suspects abnormalities that require an internal view.
Why an MRI Is Performed
Abdominal MRI scans are used for a variety of reasons. Your doctor will order an MRI if he or she suspects something is wrong in your abdominal area but can’t determine what through a physical examination.
Some of the reasons your doctor may want you to undergo an abdominal MRI scan include:
- blocked blood vessels
- disease affecting the organs
- pregnancy complications
- heart problems
The Risks of an MRI
As the test doesn’t use radiation, side effects of an MRI scan are extremely rare. There have been no documented side effects from radio waves and magnetism to date.
According to the Harvard Medical School, there are no risks associated with MRI unless you have a pacemaker or metal implant from previous surgeries or injuries.
People who are claustrophobic or get nervous in enclosed spaces may feel uncomfortable while in the machine. Your doctor may prescribe anti-anxiety medication, or in extreme cases, sedatives, to help with your discomfort.
How to Prepare for an MRI
Before the test, tell your doctor if you have a pacemaker. Depending on your type of pacemaker, your doctor may suggest another method of inspection, such as an abdominal CT scan. Some pacemaker models can be reprogrammed before an MRI so they are not disrupted during the examination.
Because the MRI uses magnets, it can attract metals. Alert your doctor if you have any type of metal implant from previous surgeries: artificial heart valves, clips, pins, plates, screws, staples, or stents.
If your doctor needs images of your colon, you may be required to use laxatives or enemas before the MRI. You also may need to fast for four to six hours before the exam.
Your doctor may require the use of a special dye to highlight an area of concern. This dye, gadolinium, is administered through an IV. While allergic reactions to the dye are rare, you should alert your doctor of any concerns before the IV is given.
How an MRI Is Performed
An MRI machine may look like it could transport you to another dimension: it has a bench that slowly glides you into a large tube attached to an opening that looks like a doughnut.
The technician will have you lie on your back on the bench and will provide you with a blanket or pillow for your comfort. The technician will control the movement of the bench using a remote control from another room, and will communicate with you over a microphone.
The machine will make some loud whirring and thumping noises as the images are being taken. Many hospitals offer earplugs, while others have televisions or headphones to help pass the time.
As the pictures are being taken, the technician will ask you to hold your breath for a few seconds. You won’t feel anything during the test as the magnets and radio frequencies—similar to those on FM radios—cannot be felt.
The entire process takes 30 to 90 minutes.
After an MRI
You do not need to do anything after an MRI except to change out of your hospital gown into your regular clothes.
If the images are projected onto film, it can take hours to get the film developed. It will also take some time for your doctor to review the images and interpret them. More modern machines display images on a computer, allowing your doctor to view them quickly.
Preliminary results from an abdominal MRI may come within a few days, but comprehensive results can take a week or more.