This prospective study evaluates two facets of gadopentetate dimeglumine (Gd-DTPA) enhanced MR imaging in 225 consecutive cranial cases in patients greater than 18 years of age: (i) patient and physician perception of adverse reactions, (ii) diagnostic value of the Gd-DTPA enhanced exam. The 225 cases included 173 head cases, 27 IAC cases, and 25 sella cases. Forty-six percent of the cases were abnormal excluding cases of mild atrophy and ischemic white matter disease judged to be related to aging and not pertinent to the patient's presenting complaint. Concerning adverse reactions, 83% of patients had no complaints. Five percent of the patients had reactions that were judged by the physician to be related to Gd-DTPA. All reactions were minor and required no therapy. In a subset of exams (115) that were blindly and independently interpreted by two board-certified, fellowship-trained radiologists, the Gd-DTPA-enhanced exam resulted in a change in diagnosis in 5%-8% of cases. Additionally, a major benefit of Gd-DTPA administration was the increased diagnostic confidence afforded by the addition of a contrast enhanced exam due to improved lesion characterization and exclusion of additional significant intracranial pathology. In 52%-69% of the abnormal cases, Gd-DTPA provided additional diagnostic information and in 26%-39% the absence of enhancement aided in interpretation. The Gd-DTPA-enhanced exam aids in the diagnosis and characterization of neoplastic disease, acoustic neuroma, subacute infarction, inflammatory disease (meningeal and parenchymal), and certain vascular abnormalities.