Abdominal MRI scan

How the Test is Performed

You may be asked to wear a hospital gown or clothing without metal fasteners (such as sweatpants and a t-shirt). Certain types of metal can cause blurry images.

You will lie on a narrow table, which slides into a large tunnel-shaped scanner.

Some exams require a special dye (contrast). The dye is usually given before the test through a vein (IV) in your hand or forearm. The dye helps the radiologist see certain areas more clearly.

During the MRI, the person who operates the machine will watch you from another room. The test most often lasts 30-60 minutes, but may take longer.

How to Prepare for the Test

You may be asked not to eat or drink anything for 4 - 6 hours before the scan.

Tell your doctor if you are afraid of close spaces (have claustrophobia). You may be given a medicine to help you feel sleepy and less anxious, or your doctor may suggest an "open" MRI, in which the machine is not as close to the body.

Before the test, tell your health care provider if you have:

• Brain aneurysm clips
• Certain types of artificial heart valves
• Heart defibrillator or pacemaker
• Inner ear (cochlear) implants
• Kidney disease or dialysis (you may not be able to receive contrast)
• Recently placed artificial joints
• Certain types of vascular stents
• Worked with sheet metal in the past (you may need tests to check for metal pieces in your eyes)

Because the MRI contains strong magnets, metal objects are not allowed into the room with the MRI scanner:

• Pens, pocketknives, and eyeglasses may fly across the room.
• Items such as jewelry, watches, credit cards, and hearing aids can be damaged.
• Pins, hairpins, metal zippers, and similar metallic items can distort the images.
• Removable dental work should be taken out just before the scan.

How the Test Will Feel

An MRI exam causes no pain. If you have difficulty lying still or are very nervous, you may be given a medicine to relax you. Too much movement can blur MRI images and cause errors.

The table may be hard or cold, but you can request a blanket or pillow. The machine produces loud thumping and humming noises when turned on. You can wear ear plugs to help reduce the noise.

An intercom in the room allows you to speak to someone at any time. Some MRIs have televisions and special headphones that you can use to help the time pass.

There is no recovery time, unless you were given a medicine to relax. After an MRI scan, you can resume your normal diet, activity, and medications.

Why the Test is Performed

An abdominal MRI provides detailed pictures of the belly area from many different views. It is often used to clarify findings from previous x-rays or CT scans.

This test may be used to diagnose or evaluate:

• Cancer and tumors
• Blood flow in the abdomen
• Blood vessels in the abdomen
• The cause of abdominal pain or swelling
• The cause of abnormal blood test results, such as liver or kidney problems
• Lymph nodes in the abdomen

MRI can distinguish tumors from normal tissues and can help the doctor determine the tumor's size, severity, and spread. This is called staging.

MRI is sometimes used to avoid the dangers of angiography, repeated radiation exposure, iodine-related allergic reactions.

What Abnormal Results Mean

An abnormal result may be due to:

• Abscess
• Acute tubular necrosis
• Cancer
• Enlarged spleen or liver
• Gallbladder or bile duct problems
• Gallstones, bile duct stones
• Hemangiomas, or others
• Hydronephrosis (kidney swelling from the backflow of urine)
• Kidney infection
• Kidney damage
• Lymphadenopathy (abnormalities of the lymph nodes)
• Obstructed vena cava
• Pancreatic cancer
• Portal vein obstruction (liver)
• Renal arterial obstruction
• Renal vein thrombosis
• Transplant rejection
• Tumor of the gallbladder

Additional conditions under which the test may be performed:

• Abdominal aortic aneurysm
• Acute renal failure
• Adenomyosis
• Atheroembolic renal disease
• Carcinoma of the renal pelvis or ureter
• Chronic renal failure
• Cystinuria
• Hydatidiform mole
• Injury of the kidney and ureter
• Insulinoma
• Islet of Langerhans' tumor
• Medullary cystic disease
• Multiple endocrine neoplasia (MEN) II
• Multiple endocrine neoplasia (MEN) I
• Nephrolithiasis
• Ovarian cancer
• Pheochromocytoma
• Skin lesion of histoplasmosis

Risks

MRI contains no radiation. To date, no side effects from the magnetic fields and radio waves have been reported.

The most common type of contrast (dye) used is gadolinium. It is very safe. Allergic reactions to the substance rarely occur. However, gadolinium can be harmful to patients with kidney problems who require dialysis. If you have kidney problems, please tell your health care provider before the test.

The strong magnetic fields created during an MRI can cause heart pacemakers and other implants to not work as well. It can also cause a piece of metal inside your body to move or shift.

Alternative Names

Nuclear magnetic resonance - abdomen; NMR - abdomen; Magnetic resonance imaging - abdomen; MRI of the abdomen

References

Pickhardt PJ. Diagnostic imaging procedures in gastroenterology. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 135.

Update Date: 11/21/2010

Updated by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.