MR of craniopharyngiomas: tumor delineation and characterization.

MR imaging and CT (with and without contrast enhancement) were performed in 20 patients with an established or clinically suspected diagnosis of craniopharyngioma. Fifteen had biopsy-proven craniopharyngioma and five had presumed craniopharyngioma based on clinical and CT findings. In two cases MR was superior to contrast-enhanced CT in demonstrating the tumor. A variable appearance on T1-weighted MR images reflected the pathologic appearance of craniopharyngiomas. High intensity on T1-weighted images corresponded to high cholesterol content or presence of methemoglobin. MR was the preferred method in the evaluation of tumor extent, especially in the cavernous sinus and posterior clival region. CT was superior to MR in detecting the presence of calcification, which with the clinical history correctly suggested the diagnosis of craniopharyngioma. Both MR and CT studies are desired initially to establish the diagnosis and to evaluate tumor extent. MR was the preferred method in detecting the presence of recurrent tumor.