[Clinico-angiographic diagnosis of space-occupying lesions of the posterior cranial fossa in children].

Superior cerebellar arteries raised above Lisholm's line is the most constant sign of a volume process in the posterior cerebral fossa. In tumors of the brain stem, the angiograms demonstrate hypertrophied arteries of the pons and changes in the position of initial segments of the upper cerebellar arteries. Tumors of the fourth ventricle in most cases cause displacement of the basilar artery to the front and the tonsillar segments of the inferior posterior cerebellar artery to the back and downward. In a lesion of the vermis of the cerebellum the artery and vein of the inferior vermis are considerably displaced to the back toward the occipital squama. Tumors of the cerebellar hemisphere may cause no changes in the position of the basilar artery in relation to Blumenbach's clivus. Displacement of the inferior posterior cerebellar artery beyond the midline indicates the side of the lesion. Demonstration of the vascular network of the tumor itself is the most important sign in topical diagnosis.