Magnetic resonance imaging (MRI) is a type of noninvasive test that uses magnets and radio waves to create images of the inside of the body. The magnets and radio waves create cross-sectional images of the abdomen, which allows doctors to check for abnormalities in the tissues and organs without making an incision.
The technology used in an MRI allows doctors to examine soft tissues without bones obstructing the view. An MRI uses no radiation and is considered a safer alternative to a CT scan.
Your doctor may order an abdominal MRI scan if you had abnormal results from an earlier test such as an X-ray, CT scan, or blood work.
Abdominal MRI scans are used for a variety of reasons. Your doctor will order an MRI if they suspect something is wrong in your abdominal area but can’t determine what through a physical examination.
Your doctor may want you to undergo an abdominal MRI scan to:
- examine blood flow
- examine your blood vessels
- investigate the cause of pain or swelling
- examine lymph nodes
Learn more: 67 Conditions that may cause abdominal swelling »
There have been no documented side effects from radio waves and magnetism to date.
Metal objects are not allowed near MRIs because the machine uses magnets. Let your doctor know if you have any metal implants, have worked in the metal industry, or have retained metal fragments from gunshot wounds, shrapnel, or another injury.
People who are claustrophobic or get nervous in enclosed spaces may feel uncomfortable in the machine. Your doctor may prescribe antianxiety medication or sedatives to help you relax.
Because the MRI uses magnets, it can attract metals. Alert your doctor if you have any type of metal implant from previous surgeries, such as:
- artificial heart valves
- clips, pins, or screws
Before the test, tell your doctor if you have a pacemaker. Depending on the type of pacemaker, your doctor may suggest a different radiological exam, such as an abdominal CT scan. Some pacemaker models can be reprogrammed before an MRI so they’re not disrupted during the examination.
Learn more: Abdominal CT scan »
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 4 to 6 hours before the exam.
Your doctor may require the use of a special dye that highlights areas 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 they give you the IV.
An MRI machine looks 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 ask you to lie on your back on the bench and will give you a blanket or pillow. The technician will control the movement of the bench using a remote control from another room, and they will communicate with you over a microphone.
The machine will make loud whirring and thumping noises as it takes images. Many hospitals offer earplugs, televisions, or headphones to help pass the time.
MRI machines are very sensitive to movement, so it’s important that you stay very still. The technician may also ask you to hold your breath for a few seconds as pictures are being taken.
You won’t feel anything during the test. The magnets and radio frequencies are similar to those on FM radios, and can’t be felt.
The entire process takes 30 to 90 minutes.
Once the test is over, you’re free to drive yourself home and continue your normal daily activities.
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 and interpret the images. 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. A radiologist will examine the images and send a report to your doctor. Your doctor will meet with you to go over your results.
MRI exams are ordered for many different reasons. Abnormal results depend on what the test was looking for. Your doctor may order more lab tests or physical exams before they can establish a diagnosis.