Metrizamide ventriculography and computed tomography in lesions about the third ventricle.

Metrizamide ventriculography was used in 24 patients with suspected lesions in and near the third ventricle. The diagnoses were aqueduct stenosis (6), upper brain stem expansions (5), third ventricular tumors (6), craniopharyngiomas (2), subarachnoid cyst (1) and normal (1). Computed tomography was used as the guide to predict the likely causes of obstruction and to determine if ventricular shunting was appropriate before or after ventriculography. Several cases required pneumoencephalography in combination with ventriculography in order to determine whether an upper brain stem lesion was intrinsic or extrinsic.