A Magnetic Resonance Imaging (MRI) scan is a noninvasive test to evaluate brain lesions and their effects on surrounding brain tissue. MRIs use a magnetic field and radiofrequency waves to give a detailed view of soft tissues of the brain in 3-dimensional slices that can be taken from the side or the top as a cross-section. An MRI image is very detailed, allowing physicians to see abnormalities that otherwise may be difficult to identify.
A dye (contrast agent) may be injected into the patient’s bloodstream to allow a more precise view of the targeted body tissues. This dye contains gadolinium, which moves through the blood stream and is absorbed in certain tissues. Since the gadolinium has magnetic properties, the targeted tissues are enhanced on the scan.