Visualization of small extracanalicular neurilemomas by metrizamide cisternographic enhancement

Metrizamide (Amipaque) computerized tomography cisternography (CTC) provides a rapid, simple, and accurate radiographic modality of intrathecal enhancement for detecting and morphologically characterizing cerebellopontine (CP) angle masses. The technique is of especial value in masses greater than 1.5 cm that are not detected on intravenously enhanced computerized tomography. Metrizamide CTC was used in six patients with no CP angle mass and in four patients with acoustic neurilemomas.