Magnetic resonance imaging (MRI) creates two-dimensional images of the internal structures of the body. MRI works by using a large magnetic field, pulses of radio waves, and a computer to produce the images.
Patients usually do not need any special preparation before an MRI.
Patients should inform their physicians if they have any implants or other metal items inside their body. Patients should also inform their physician if they are prone to claustrophobia or anxiety.
Individuals who are ineligible to undergo an MRI include those who:
- Weigh more than 300 pounds;
- Have a pacemaker or other devices or implants;
- Are unable to lie still on their back for any extended period of time;
- Are pregnant or suspect they are pregnant; and
- Are claustrophobic or otherwise prone to extreme anxiety.
WHAT TO EXPECT
An MRI is performed in a hospital or an outpatient healthcare facility. The technician will instruct the patient to lie still on his or her back on a narrow table. The table slides into a tunnel-like tube within the scanner. As the patient slides through the tube, he or she is exposed to the magnetic field and the pulsing radio waves, which create the images.
Patients can generally resume usual activities and diet immediately following the MRI. However, patients that receive sedatives should not drive for at least 24 hours following the procedure.