Virtual endoscopy (VE) of the basal cisterns: its value in planning the neurosurgical approach.

Virtual endoscopy (VE) is a postprocessing technique based on a diverging ray casting algorithm to create perspective 3 D-images from computed tomographic angiography (CTA) and high resolution magnetic resonance imaging (MR) data. By applying VE to aneurysms, tumors, and vascular compression syndromes within the basal cisterns, endoscopic-like views of these structures are achieved from an intracisternal point above the cranial base. These views closely simulate the surgeon's impression during intraoperative endoscopy or microscopy and facilitate preoperative planning of different approaches.