A shoulder MRI scan is a magnetic resonance imaging of the shoulder that uses radio waves and a powerful magnetic field to create detailed images of the bones including soft tissues such as bones, muscles, tendons, blood vessels, cartilage, and ligaments within the shoulder joint. It does not use radiation, unlike x-rays. In most cases, MRI provides information about structures and soft tissues in the body that can’t be seen using an ultrasound, an x-ray, or a CT scan. This is usually recommended by the doctor to evaluate injuries and to determine potential problems that have been found in other imaging tests like ultrasound and x-rays. It can also help the doctor diagnose pain in the shoulder area or to have a better understanding of the condition that is causing the shoulder pain.
In MRI scan, your body is placed inside the magnet where the shoulder is inside the magnetic field. The shoulder MRI scan operates by spawning a magnetic field that aligns the water molecules in the body temporarily. The aligned particles are used by radio waves to create faint signals that are recorded by the machine as images. MRI can detect changes in the structure of tissues and organs. It also has the ability to find disease or tissue damage such as a tutor or infection.
Some MRI may require a contrast dye which is normally given through an IV before the test. The contrast dye can be injected on the hand, forearm, or shoulder. The contrast dye helps the radiologist see specific areas more clearly.
Why is a Shoulder MRI Scan Done?
The shoulder is the most used joint in the body because it is composed of three major bones that are used on a daily basis. Since it is used a lot, it is prone to a lot of problems and injuries.
The main reason why a shoulder scan may be recommended by the doctor is that of pain or injury which may be caused by a strong impact or a long-term effect of overusing the joint. These are the different conditions or problems that may require a shoulder MRI scan:
- Rotator cuff tears and impingement
- Dislocation of the shoulder joint
- Bone fractures
- Arthritis and other degenerative joint diseases
- Sports-related injuries
- Torn tendons and ligaments
- Worn-out cartilage or tears in the cartilage
- Bone tumors or infections
- Decreased range of motion
- Unexplained swelling and pain in the shoulders
In some instances, the doctor is able to track the effect of medications, physical therapy, or surgeries on the shoulder with the help of an MRI scan.
Risks Posed by a Shoulder MRI Scan
Since MRI doesn’t expose the body to radiation unlike x-rays, MRI scans pose fewer risks. There haven’t been any reported side effects from the magnets and radio waves used in MRI scan. Here are some precautions for people with positive conditions who are at a higher risk when doing an MRI scan.
- Dye Allergy
There are some individuals who might have an allergic response to the contrast dye that may sometimes be required to have a clearer image of the blood vessels when doing the MRI scan. These allergies are often mild and can be easily treated with medication.
It’s important to inform your doctor of any allergies especially if you have had experienced an allergic reaction to contrast dye in the past.
- Metal Implants
Implants that contain metal may malfunction or cause problems during the MRI scan. The strong magnetic fields that are generated during the MRI scan may cause implanted pins or screws and heart pacemakers to malfunction. It may also result in the moving or shifting of a piece of metal inside the body.
Inform the doctor in case you have any of these implants:
- Artificial joints
- Metal clips from aneurysm surgery
- Artificial heart valves
- Cochlear implant
- Metal fragments or bullet
Depending on the type of pacemaker, the doctor may recommend another way of evaluating you shoulder pain such as CT scan. There are some models of pacemaker that can be reprogrammed before an MRI scan so that they will not be rattled during the MRI scan.
- Nephrogenic systemic fibrosis
This condition is a rare complication of MRI that may be a result of injecting high doses of gadolinium-based contrast material for individuals who have kidney problems that need dialysis.
Mothers are not allowed to breastfeed for 24 up to 48 hours after they have been given a contrast dye. They should wait for the dye to wear off minimize putting their babies at risk.
- Excessive Sedation
There may be risks of excessive sedation if sedation is used. Wait for the sedative to fully wear off before going home.
MRI Scan Results
MRI lasts for 30 to 60 minutes but may also take longer. The results may take days to be processed but for more comprehensive results, it may take a week or more. The doctor may require more tests to properly diagnose your condition.
Results are normal if there are no problems seen in the shoulder and its surrounding tissues.
Abnormal test results may be caused by:
- Abnormal osteonecrosis
- Biceps tear
- Bone infection
- Bursitis in the shoulder area
- Cancer / tumor
- Cyst on the shoulder
- Fractured or broken shoulder bone
- Inflammation of the shoulder
- Labral Tear
- Rotator cuff tear or tendinitis