Metrizamide-enhanced CT for evaluation of brainstem tumors.

Computed tomography (CT) of the brain has been used extensively to evaluate both supraand infratentorial mass lesions . However, even with the use of intravenous contrast enhancement, visualization of small brainstem lesions has not been totally satisfactory . The differentiation of intrafrom extraaxial lesions has also at times proved difficult and frustrating. Computed tomography combined with intrathecal enhancement using metrizamide provides excellent delineation of the normal anatomy of the basal cisterns and brainstem [1-4]. Small aberrations of the normal architecture can be easily seen allowing early diagnosis and accurate localization of small mass lesions.