A hip MRI, or magnetic resonance imaging, is a diagnostic medical imaging test physicians can use to check for certain hip problems. This may include avascular necrosis of the femur at the hip joint as well as other fractures and joint problems. Traditional MRI units look like large round tubes that are covered in a large magnet. The magnetic field produced by the machine is analyzed by a computer and processed into an image that shows a picture of the body part being studied, including the bones and soft tissues. A radiologist or physician can then analyze the images to diagnose hip problems that might need further intervention, such as surgery.
Most of the time, a hip MRI is a completely noninvasive procedure, making it a better first choice than an invasive technique, such as exploratory surgery. In some cases, patients undergoing a hip MRI will have an intravenous (IV) line inserted into their arms or hands to inject a contrast material that allows certain tissues to show up darker on the images produced by the scan. Most MRIs take no more than 30 minutes, but some procedures can take up to an hour if the radiologist has to take several images of the same place.
Patients who require a hip MRI are usually scanned at a hospital or imaging facility on an outpatient basis. The most important thing a patient can do to help the images come out clearly is to remain completely still while undergoing the MRI, as moving can distort the image. Some patients are strapped down to a table that slides inside the MRI machine to help them remain still. Claustrophobic patients may be given a sedative to help them relax and remain motionless during the procedure, but this usually isn’t necessary.
While most people can undergo a hip MRI safely, people with certain medical devices or implants cannot be scanned in an MRI machine due to the magnetic field created by the equipment. People with cochlear implants, internal pacemakers, and certain types of brain aneurysm clips or blood vessel coils cannot have a hip MRI. Patients should tell their doctors about any implanted medical devices or any other metal that may be present in their bodies from prior injuries or accidents.
There is no risk or recovery time associated with a hip MRI for most patients. Those who require sedation may need a day to rest before returning to their normal activities, but the procedure itself is painless and harmless. Most hip MRI patients do require follow-up visits with their physicians to discuss the results of the test and necessary future steps to treat diagnosed hip problems.