Magnetic Resonance Imaging Scan (MRI)
The MRI, which uses magnetic fields, not X-rays, to provide detailed images, is more sensitive than the CT in detecting a brain tumor's presence. The MRI is a preferential imaging test because it outlines the normal brain structure in unique detail. The test procedure is slightly more time consuming as the patient lies inside a cylinder-type machine for about one hour. A special dye may also be injected in the bloodstream during the procedure (MRI angiogram) to distinguish tumors from healthy tissue.