Forty patients with symptoms of intracranial disease were studied with magnetic resonance before and after intravenous injection of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA). The T1- and T2-weighted images were obtained in all patients. Ninety brain lesions were found in 36 patients, including primary (20 patients) and metastatic (six) tumors, hemorrhage (one), progressive multifocal leukoencephalopathy (one), cysticercosis (one), infarction (four), and postoperative changes (four). Postcontrast images revealed lesions not seen on precontrast scans in eight (20%) patients. Also, the postcontrast images showed a change in appearance of the lesions in 20 (50%) that provided helpful information for assessing the abnormality in 20 cases (50%). Gadolinium-DTPA did not obscure any of the lesions seen on precontrast scans. It improved conspicuity, helped characterize and delineate the extent of lesions, and increased the sensitivity for detection of cerebral abnormalities.