A knee MRI is a medical imaging study performed to get a look at the inside of the knee. It can be used as a diagnostic tool when a doctor suspects that there is something 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, she or he is asked to remove all metal objects, and may be asked to get into a hospital gown. Metal objects cannot be present in the MRI room because of the magnet inside the MRI machine. Patients who have medical implants should disclose them to their doctors before getting an MRI, in case there is a risk.
Once the patient is ready, she or he is helped onto an MRI table, and pillows are used to brace 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 inside the machine before it starts. During the MRI itself, the machine tends to generate very loud noises, and patients are often issued with headphones. Many hospitals provide patients with music to listen to so that they can relax.
The knee MRI can take 30 minutes to an hour. It is important to stay still during this period. Patients who know that they will have trouble lying down may ask if they can take a sedative or a drug for pain management. Sedatives may also be offered if a patient experiences claustrophobia, so that the patient will be able to relax inside the MRI room.
If the image is clear, the results of the MRI will be made available to the patient very soon, and the doctor will talk about the implications of the results and possible treatment options. Sometimes, the image is not totally clear, and a doctor may ask that an MRI with contrast be performed. In a contrast knee MRI, a contrast dye is injected. When the MRI is performed, the dye will highlight various areas of the joint. Before contrast is injected, the patient should review her or his allergies, to confirm that it will be safe to use contrast.