Comparison of Magnetic Resonance Imaging with Computed Tomography in the Detection and Characterization of Intracranial Tumors

Abstract

The rapid development of clinical magnetic resonance imaging (MRI) and its recognition as a valuable tool in neurodiagnosis have generated excitement and enthusiasm rivalling that associated with the introduction of computed tomography (CT) a decade ago. Magnetic resonance imaging has several advantages over X-ray CT. The multiple physical properties of tissue that determine image contrast in MRI permit superior detection and characterization of altered tissue. The relatively small alterations in focal water concentration caused by many brain disorders produce proportionally larger alteration in intensity of the MRI signal than of the CT signal. Differential sensitivity of MRI to resonating protons found in other molecular substrates, such as fat or hematoma, may yield additional information of histologic significance. The ability of MRI to visualize blood vessels provides anatomic landmarks in normal patients and assumes diagnostic importance in the presence of vascular lesions. Finally, MRI has no known biologic hazards, iodinated intravenous contrast agents are not required, bone artifacts are eliminated, and images may be obtained directly in any plane.