MRI and other advances in medical imaging have made it increasingly possible to detect arthritis in its early stages and assess its severity.
MRI scans are a powerful tool for diagnosing arthritis, as they are more sensitive than traditional X-rays and ultrasound imaging.
MRI is more expensive than some other imaging tests, so some clinics may only use it in clinical trials or for evaluating particular conditions, such as spondyloarthritis.
Arthritis is a condition that causes pain and inflammation in the joints. Detecting arthritis early can help people access effective treatment sooner and slow the progression of the disease.
In this article, learn more about what arthritis looks like on an MRI scan, as well as what to expect during the procedure.
Arthritis mostly affects the joints and surrounding tissues. Any damage in these areas will be visible on an MRI scan.
A radiologist or other type of doctor will look for the following signs of arthritis:
- damage to the cartilage
- bone spurs (osteophytes)
- tears in the ligaments
- an increase in bone density
- synovitis, or inflammation of the synovial membrane in joints
- bone marrow edema, which is a build-up of fluid in the bone marrow
- joint effusion, commonly called ‘water on the knee’
A CT scan may be better for evaluating bone density. A doctor can also use a DEXA scan or plain X-ray.
While bone spurs show up on an MRI scan, X-ray images are the best option for detecting these. MRI is better for looking at soft tissue over bone.
Compared to other medical imaging techniques, MRI scans are highly sensitive and provide detailed images. When looking at a joint, they can show both the bone and surrounding tissues.
MRI can show whether there has been damage to the bone, which can occur in later stages of the disease. It can also identify if tiny bone fragments have broken off.
MRI can also provide detailed images of the surrounding tissue, which allows doctors to detect inflammation in the soft tissues much earlier than if they used an X-ray.
MRI can identify bone erosions and assess how much the arthritis is wearing away the cartilage lining the joint before this damage is visible on an X-ray.
Two of the most common types of arthritis a doctor may look for using MRI are:
- Osteoarthritis: A condition where the tissue that covers the bones in joints breaks down. It usually occurs with age or due to a prior joint injury and causes the joints to rub against each other.
- Rheumatoid arthritis: An autoimmune disease, causing inflammation in the synovial tissue that lines the joints. Autoimmune diseases occur when the immune system mistakenly attacks its own tissues and body parts.
MRI can clearly identify some of the signs of osteoarthritis, including whether cartilage is wearing away.
MRI can also detect signs of rheumatoid arthritis, but a doctor will also use a variety of other tests, such as blood tests.
Doctors can distinguish between soft tissues and fluids using MRI. This means they can assess signs of rheumatoid arthritis, such as inflammation and the condition of the synovial membrane.
The synovial membrane covers joints and protects them. It can be enlarged (synovial thickening) in people with rheumatoid arthritis.
Having an MRI scan is a very safe procedure with few side effects in most people.
Typically, people having an MRI scan do not need to make any special preparations, though they may need to change into a hospital gown.
As MRI machines use powerful magnets, it is essential to remove any metal objects, such as watches or jewelry, before the scan.
The MRI scanner is a large, donut-shaped machine. The person having the scan will lie down on a bed in the middle of the scanner. The exact position will vary depending on what part of the body needs scanning.
A radiologist or technician will explain the procedure and any safety information before starting the scan. The duration of the scan can be anywhere between 45—60 minutes per body part.
During the scan, it is important to remain as still as possible. The scanner will make loud noises while it is operating, which might make some people feel uncomfortable or anxious. Technicians might offer earplugs to help block this out, or a person may be able to listen to music.
There is a two-way intercom inside the scanner, which a person can use if they have any concerns or experience problems. It is always possible to stop an MRI scan at any point. This can be through an alarm button inside the scanner or using the intercom.
People with claustrophobia or who find the experience very stressful may have the option to take a sedative during the scan or use an open-MRI machine.
Some people, such as those with implanted pacemakers, are unable to have an MRI scan.
A doctor will always assess a person’s physical symptoms and medical history during a diagnosis. They may record temperature, heart rate, or check for swollen glands.
In some cases, medical imaging will be necessary to assess any damage or confirm the diagnosis. While MRI is one option, X-rays can show bone spurs and whether the bones in joints have become too close.
Another possible test is a CT scan. These are useful for detecting bone lesions.
A doctor may also use an ultrasound scan to detect problems in the synovial membrane or tendons.
It is normal to experience minor aches or pains around the joints. This becomes more common with age or after vigorous exercise.
But if joint pain lasts several days, comes with swelling, or makes it difficult to perform daily tasks, it is best to see a doctor.
MRI scans are very useful for diagnosing arthritis. They can provide detailed images of the joint and surrounding tissues.
These images help doctors to make a diagnosis and assess the severity of the condition.
Getting an MRI scan for arthritis is generally a safe procedure. In some cases, doctors may suggest other tests as well, such as X-rays and ultrasounds.