Magnetic resonance imaging (MRI) scans are used to help doctors diagnose problems with bones, tissues, and internal organs. It is common for a person who has suffered a severe knee injury to undergo a meniscus MRI so that physicians can check for tears in the joint tissue. An MRI can reveal the extent of damage to the important tissue that provides stability and cushioning for the knee. Going in for a meniscus MRI can cause anxiety in a person who has never had an MRI before, but learning what to expect beforehand helps to reduce fears and confusion. Ultimately, an individual can expect a painless procedure that will only last about 30 minutes.
An MRI machine is a large tube that uses magnetic impulses to create an image of internal body parts. Electromagnetic waves excite hydrogen ions within cells, causing them to align a certain way. A second set of magnetic waves is introduced at a different angle to agitate the ions. When magnetic fields are turned off, the ions resonate and finally settle. By recording the movement of ions, the MRI machine can produce highly accurate images of internal structures that reveal damage to meniscus tissue.
During a meniscus MRI, the patient is usually instructed to lie down on a comfortable table at the base of the MRI tube. In most cases, only the damaged leg needs to be placed inside the tube. Technicians are present during the procedure to talk to the patient, answer questions, and explain what is going on. It is important for a patient to remain very still during the procedure so that results will be accurate. It is common to hear loud clicks or knocks, which are simply the magnetic fields being turned on or off.
Most meniscus MRI procedures only take 30 to 45 minutes, after which the patient is allowed to redress and leave. MRI results are not available immediately following a procedure. Specialists must first analyze and interpret the scans, and deliver them to doctors. Patients usually receive the results from their doctors within a week. Physicians explain the findings and determine the best course of treatment, which may include physical therapy sessions, medication, or surgery.
It is important to speak with a doctor about any lingering medical conditions before going in for a meniscus MRI. Since the machine uses high-powered magnets, the presence of any metal objects inside the body can disrupt results and pose health hazards. A patient with a pacemaker or an artificial metal hip, for example, may not be able to receive an MRI. Doctors and technicians can determine the risks and decide on other diagnostic procedures if necessary.