Magnetic resonance imaging, known as MRI, is a painless and safe scan. It is used to diagnose a wide range of problems or monitor recovery from surgery. It does not use radiation, and there is no recovery time required. Here’s what you need to know about a shoulder MRI.
What Is an MRI Used For?
An MRI uses a computer, magnetic fields, and radio waves to make detailed image slices of your body, called cross-sections. It’s considered the gold standard test for soft tissue problems, because these images show only a few ultra-thin layers of tissue at a time. This helps doctors pinpoint problems.
Your doctor will recommend this test to look at soft tissue damage in your shoulder and any other joint, ligament, or bone problems. These include:
- Degenerative joint disorders like arthritis
- Shoulder impingement, or pressure on tendons or nerves in the shoulder
- Rotator cuff injury
- Torn ligaments
- Sports injuries
- Repetitive strain that causes injury and pain
- Bone infections
- Shoulder pain that doesn’t get better with treatment
- Trouble moving your shoulder
- Shoulder healing after surgery
What is an MRI with Contrast?
Some MRIs are done with a special dye, or contrast agent. Before the scan, the dye is injected with an intravenous needle or IV. It collects around tissues and cells and makes it easier to see parts of your shoulder.
Your doctor might do a shoulder MRI with contrast to get better images. The contrast is less likely to cause allergic reactions than other types, but it might feel cool when it’s injected in your vein.
How Is an MRI Done?
The MRI machine is a long, narrow, magnetic tube with open ends. A technician will help you lie on a table, which slides into the tube opening. A technician operates the machine and watches the images from another room.
The MRI is painless, but some people feel nervous because it's a small space. If you think you might have problems, talk to your doctor. They might be able to give you a sedative that can help you relax. This is important, because you need to be still during the scan.
How Long Does a Shoulder MRI Take?
The scan lasts anywhere from 15 to 90 minutes, though it can take longer. Sometimes people find the table is cold after being there for a while. The technician can give you a blanket to make it more comfortable.
How Do I Get Ready for a Shoulder MRI?
You will have to answer some questions about implants and other medical devices before your MRI. The machine is magnetic and might cause damage to your body if you have internal metal devices. These include some types of:
- Brain aneurysm clips
- Cochlear implants
- Artificial heart valves
- Artery stents
- Recent artificial joints
- Vagal nerve stimulators
Once you’re cleared to have the MRI, you’ll receive instructions from the imaging lab about how to get ready. In some cases, your doctor might ask you not to eat or drink for 4 to 6 hours before the exam. You might also be asked to:
- Wear comfortable, loose clothes with no zippers, snaps, or buttons
- Remove all jewelry
- Remove hearing aids
- Keep your belongings outside the MRI room
- Remove hairpins
- Take out any removable mouth appliances
What Happens After the MRI?
A radiologist will review your MRI images before making a report that you will review with your doctor.
This report is a description of anything irregular the radiologist sees in the images. Since the scan shows cross-section slices of your shoulder, the radiologist can’t be completely certain what they see. The report might use terms like “ possible tear” or “probable tear,” for example.
What Is a Normal vs. Abnormal Shoulder MRI?
Normal shoulder MRI results mean that no problems are visible on your scan. Abnormal results mean that the scans show problems with your shoulder. This could be anything from a tear to arthritis to a cyst. Your doctor will help you understand your results and the next steps for treatment.