Computer tomography of cerebellopontine angle lesions

Computer tomography (CT) was used in 53 consecutive patients with a working diagnosis of cerebellopontine angle tumor. The CT was performed with the 160 X 160 matrix scanner, height of sections was 13 mm. Metrizoate sodium (1.5 ml/kg of body weight) was used for tumor enhancement. Seventeen CT scans revealed tumors; one patient proved at operation to be false-positive. Thirty-six CT scans revealed no tumors; two examinations may prove to be false-negative, but surgical verification has so far not been obtained. The smallest tumor demonstrated by CT extended 7 mm into the angle, while one of the possible false-negative CT scans after iophendylate injection cisternography showed a tumor extending 5 mm into the angle. It is concluded that CT is a harmless, noninvasive neuroradiological procedure, and should precede invasive procedures. It can be used safely in patients with increased intracranial pressure.