[Delineation of the cisternal architecture with three-dimensional CT cisternography and its transparent imaging].

We used three-dimensional imaging of the cisternal architecture with perspective volume rendering of CT cisternography in patients with unruptured cerebral aneurysms. Selective changes in the opacity chart of computed tomographic values, based on the use of a function of downward slope, represented the contour of the structures located in the cisternal space. In addition to this, using a spiked peak curve, it was possible to show the contour of the outer wall of the cisternal structures as a series of rings, which provided a transparent view inside and/or outside the cistern through the spaces between the rings. Transparent imaging technique allowed direct visualization of the underlying objects and offered an extensive perspective view of the anatomical architecture of the cisternal structure, including an aneurysm, major basal arteries and optic pathway, in a single view. Three-dimensional CT cisternography may be a useful adjunct for the diagnosis of the cisternal architecture in relation to the surrounding cerebrospinal fluid, and for simulation of the surgical procedures considered for lesions occupying intra-cisternal space, including cerebral aneurysms.