Health Encyclopedia - Test
Shoulder MRI scan
A shoulder MRI (magnetic resonance imaging) scan is a imaging test that uses energy from powerful magnets and to create pictures of the shoulder area.
It does not use radiation (x-rays).
Single MRI images are called slices. The images can be stored on a computer or printed on film. One exam produces dozens or sometimes hundreds of images.
Related tests include:
MRI - shoulder; Magnetic resonance imaging - shoulder
How the Test is Performed
How to Prepare for the Test
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 in 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. You will need to lie still. Too much movement can 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 lets you to speak to someone at any time. Some MRIs have televisions and special headphones to help you pass the time.
There is no recovery time, unless you received medicine to relax. After an MRI scan, you can go back to your normal diet, activity, and medications.
Why the Test is Performed
Your doctor may order this test if you have:
- A mass that can be felt during a physical exam
- An abnormal finding on an x-ray or bone scan
- Shoulder pain and fever
- Decreased motion of the shoulder joint
- Fluid buildup in the shoulder joint
- Redness or swelling of the shoulder joint
- Shoulder dislocation
- Shoulder weakness
- Shoulder pain and a history of cancer
- Shoulder pain that does not get better with treatment
What Abnormal Results Mean
Some possible causes of abnormal results may be:
- Bone infection (osteomyelitis)
- Broken or fractured shoulder bone
- Bursitis in the shoulder area
- Anormal Osteonecrosis (vascular necrosis)
- Rotator cuff tear
- Rotator cuff tendinitis
- Shoulder inflammation (frozen shoulder)
- Tumor (including cancer
- Labral tear
- Cyst in the shoulder
This list does not include all possible problems. Talk to your health care provider with any questions and concerns.
Tests that may be done instead of an MRI of the shoulder include:
- Shoulder CT scan
- X-ray of the shoulder
A CT scan may be preferred in some emergency cases, since it is faster and usually available right in the emergency room.
Wilkinson ID, Paley MNJ. Magnetic resonance imaging: basic principles. In: Grainger RC, Allison D, Adam, Dixon AK, eds. Diagnostic Radiology: A Textbook of Medical Imaging. 5th ed. New York, NY: Churchill Livingstone; 2008:chap 5.
DeLee JC, Drez D Jr, Miller MD, eds. DeLee and Drez's Orthopaedic Sports Medicine. 3rd ed. Philadelphia, PA: Saunders Elsevier; 2009:chap 17.
Reviewed By: C. Benjamin Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang