MRI is a painless technique that usually takes about 20 minutes. MRI usually is done as an outpatient test in a special scanning area of a hospital or in a scanning facility. You will be asked to remove all metal jewelry and to lie on a scanning table. If a cylindrical scanner is being used, the table will slide into the narrow opening into the MRI cylinder. In an open MRI, the table will slide so that the part of your body being scanned is surrounded by the scanning element, or the machine will move over you as you lie on the table. You will need to lie very still during the procedure, and you will periodically hear loud knocking noises as the scanner works. The technicians operating the machine will be in another room. However, they will be able to talk to you through speakers in the machine or through earphones.