Radiology of the ambient cistern. Part I: Normal.

The angiographic and high-resolution, thin-section CT appearance of the normal ambient cistern is correlated with anatomic dissections and sections of normal, formalin-fixed cadaver brains. Each of three separate anatomic segments of the ambient cistern--the supratentorial segment, the tentorial edge and the subtentorial segment--has a characteristic CT appearance that can be correlated with specific vascular structures on routine angiography.