None, unless the patient has an implanted pacemaker or other implanted metal devices. To obtain two-dimensional views of an internal organ or structure, especially the brain and spinal cord. To assess response to treatment, especially cancer chemotherapy or radiation therapy. To assess sports-related injury to bones and joints. How it works MRI uses a powerful magnetic field and radio waves to alter the natural alignment of hydrogen atoms within the body.
Computers record the activity of the hydrogen atoms and translate that into images.
All jewelry, hair clips, and other metal objects must be removed. Otherwise, no special preparation is required. At certain points during the test, the noise will stop and you will be able to hear instructions from the doctor or technician administering the test. Variations Echoplanar MRI is a new technique that allows for rapid accumulation of data such as cardiac motion. After the test You can resume your pretest activities immediately.