What Is a Shoulder MRI Scan?
An MRI scan uses magnets and radio waves to capture images
of your body’s internal structures. It doesn’t involve a surgical incision. The
scan allows your doctor to see your bones as well as soft tissues of the body,
including muscles, ligaments, tendons, and even nerves and blood vessels.
While an MRI can be performed on any part of your body, a
shoulder MRI scan specifically helps your doctor see the bones, blood vessels,
and tissues in your shoulder region.
A shoulder MRI helps your doctor diagnose potential
problems found in other imaging tests, such as X-rays. It also helps your
doctor diagnose unexplained pain in the area or better understand the condition
causing your shoulder symptoms.
An MRI scan works by generating a magnetic field which
temporarily aligns the water molecules in your body. Radio waves use these
aligned particles to produce faint signals, which are recorded as images by the
Unlike X-rays and CT scans, an MRI uses no radiation and
is considered a safer alternative, especially for pregnant women and children.
Why a Shoulder MRI Scan Is Performed
The shoulder is a large and complicated joint that we use
on a daily basis. It’s made up of three major bones. This makes it the most
mobile joint in the body. As a result, numerous problems can affect our
Pain or an injury are the main reasons your doctor might
order an MRI scan. The injury could be the result of an impact, or simply the
effect of long-term wear and tear on the joint. Specific problems that could
require a shoulder MRI scan include:
- dislocation of the shoulder joint
- degenerative joint diseases, such
- rotator cuff tears
- bone fractures
- sports-related injuries
- unexplained pain and swelling
- decreased range of motion
- Infections or tumors
In some cases, an MRI scan can help your doctor track the
effect of surgeries, medications, or physical therapy on your shoulder.
Risks of a Shoulder MRI Scan
MRI scans carry few risks since they don’t use radiation.
To date, there have been no documented side effects from the radio waves and
magnets used in the scan. Still, people with certain conditions do face some risks.
If you have implants containing metal, it can cause
problems with an MRI. The magnets used in an MRI can interfere with pacemakers
or cause implanted screws or pins to shift in the body. Be sure to tell your
doctor if you have any of the following implants:
- artificial joints
- artificial heart valves
- metal clips from aneurysm surgery
- bullet or other metal fragments
- a pacemaker
If you have a pacemaker, your doctor may suggest another
method for inspecting your shoulder area, such as a CT scan. This depends on
your type of pacemaker. Some pacemaker models can be reprogrammed before an MRI
so that they are not disrupted during the examination.
Some people can have an allergic reaction to the contrast
dye. Contrast dye helps provide a clearer image of the blood vessels. The most
common type of contrast dye is gadolinium. According to the Radiological Society of North America (RSNA), these allergic reactions are
often mild and easily controlled with medication. Be sure to tell your doctor
about any allergies or if you’ve had an allergic reaction in the past.
Women shouldn’t breast-feed 24 to 48 hours after they have
been given contrast dye. They need to wait for the dye to leave their bodies.
How to Prepare for a Shoulder MRI Scan
Tell your doctor if you have any metal in your body from
previous procedures or injuries. You’ll need to remove any metal from your body,
including jewelry and body piercings before the test. You’ll change into a
hospital gown so that metal on your clothing doesn’t affect the test.
If you’re claustrophobic or have a hard time in enclosed
spaces, you may feel uncomfortable while in the MRI machine. Your doctor may
prescribe anti-anxiety medication to help with your discomfort. In some cases,
you may also be sedated during the test.
How a Shoulder MRI Scan Is Performed
If your test requires the use of contrast dye, a nurse or
doctor will inject it into your bloodstream through an intravenous line. You
may need to wait for the dye to circulate through your body before beginning
An MRI machine is a giant white tube with a sliding bench
attached to it. You’ll lie on your back on the table and slide into the
machine. A technician will place small coils around your shoulder to improve
the quality of the scan images.
The technician will control the movement of the bench
using a remote control from another room. They can communicate with you via a
The machine will make loud whirring and thumping noises as
the images are being recorded. Many hospitals offer earplugs. Others have
televisions or headphones to help you 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
A typical shoulder MRI takes 45 minutes to an hour to
After a Shoulder MRI Scan
After your shoulder MRI, you’re free to leave the hospital
unless your doctor tells you otherwise. If you were given a sedative, you need
to wait to drive until the medication has fully worn off. Or, you can arrange
for a ride home after the test.
If your MRI images were projected onto film, it might take
a few hours for the film to develop. It will also take some time for your
doctor to review the images and interpret the results. More modern machines
display images on a computer, so your doctor can view them quickly.
The initial results from an MRI scan may arrive within a
few days, but comprehensive results can take up to a week or more.
When the results are available, your doctor will call you
in to review and explain them. More tests may be necessary to make a diagnosis.