Radiological diagnosis of pontine angle tumours.

The following methods of radiological examination are suitable aids in the diagnosis of pontine angle tumours: plain radiographs and tomograms of the petrosal bone, cisternography of the pontocerebellar cistern with positive- und negative-contrast media, vertebral arteriography and computer tomography. In some 80% of cases of pontine angle tumour, plain X-rays and tomograms can disclose changes. In the case of vestibulocochlear neurinoma confined to an intracanalicular localization, only cisternography with a positive-contrast medium supplies diagnostic information. Cisternography with a negative-contrast medium is a suitable method of radiological examination in the case of larger vestibulocochlear neurinomas, which protrude into the pontocerebellar cistern, and also for the remainder of pontine angle tumours. The technique we use in this cisternography is described and evaluated with reference to 28 patients.