An arthrogram helps your doctor diagnose unexplained shoulder, hip, knee or other joint pain. It can show problems with ligaments, tendons and cartilage with excellent clarity—problems that might not show up on standard imaging like X-ray. It can also help determine the best treatment option for you. If you’ve already had joint replacement surgery, it may be used to evaluate the joint to ensure that it is working properly.
At Expert MRI, we perform both MR and CT Arthrograms. This simply means that either MRI (magnetic resonance imaging) or CT (computed tomography or “cat scan”) is used to perform the procedure. The one you will have will depend on several factors, including the joint being evaluated and whether or not you are allergic to certain contrast materials.
In either case, the arthrogram enables the joint to be imaged in several positions. Sometimes, a traction device may be used to stretch the joint to allow the radiologist a wider view of the joint. In other cases, items like pillows or sand bags may be used to help position the joint for optimal imaging.
MRI uses a powerful magnetic field, radiofrequency pulses and a computer to produce detailed pictures of soft tissues and bone. It does not use any form of ionizing radiation, like with x-rays. MR arthrography involves the injection of a contrast material called gadolinium into the joint before the test. The contrast material outlines the structures within the joint and allows them to be more easily seen and evaluated by the radiologist.
CT is an imaging system that revolves around the patient, taking multiple x-rays at different angles. A computer then processes these into cross sectional images of anatomy. Because CT arthrography is X-ray based, a different type of contrast material containing iodine is used.
Arthrography is particularly effective for detecting tears or lesions of the structures and ligaments of the joints, especially the knee, wrist and elbow, as well as rotator cuff tears or damage from a shoulder dislocation.
If you’ve had unexplained joint pain, an arthrogram could be the test that leads to an accurate diagnosis.