A knee MRI is a medical imaging study done to look inside the knee. It can be used as a diagnostic tool when a doctor suspects something is wrong with the knee, or it can be used as a follow-up procedure to see how well a patient is healing. Knowing what to expect can make the experience more pleasant, especially for younger patients.
Knee MRIs are performed as outpatient procedures. When the patient arrives at the hospital, they are asked to remove all metal objects and may be asked to change into a hospital gown. Metallic objects cannot be present in the MRI room due to the magnet inside the MRI machine. Patients who have medical implants should disclose them to their doctors before having an MRI, in case there is a risk.
Once the patient is ready, he or she is assisted on an MRI table and pillows are used to support the knee and hold it in place. If the hospital has an open MRI machine, it will often be used for a knee MRI for patient comfort. If the MRI machine is closed, the MRI table will slide into the machine before it starts. During the MRI itself, the machine tends to make very loud noises, and patients are often given hearing aids. Many hospitals provide patients with music to listen to so they can relax.
The knee MRI can take anywhere from 30 minutes to an hour. It is important to remain still during this period. Patients who know they will have trouble lying down may ask if they can take a sedative or pain control medication. Sedatives may also be offered if a patient experiences claustrophobia, so that the patient can relax inside the MRI room.
If the image is clear, the results of the knee MRI will be available to the patient very soon, and the doctor will discuss the implications of the results and possible treatment options. Sometimes the image is not entirely clear, and a doctor may order an MRI with contrast. In a contrast MRI of the knee, a contrast dye is injected. When the MRI is done, the dye will highlight various areas of the joint. Before injecting the contrast, the patient should check her allergies to confirm that it is safe to use the contrast.