Virtual realty based visualization of intra- and extracranial vessels

Virtual reality is used in the area of the central nervous system, especial ly for virtual endoscopy of cerebrospinal fluid spaces or vessels. Extralum inal views are more important than endovascular views concerning evaluation of complex vascular topographies. For extraluminal evaluation "virtual cis ternoscopy" can be used to produce virtual flights around vessels. This met hod is well suited for analysis of intracranial vascular findings, such as aneurysms or malformations. For virtual cisternoscopy an adequate postproce ssing technique is necessary, as provided by perspective volume rendering. For evaluation of extracranial arteriosclerotic changes virtual flights are not necessary. In this case, simple maximum intensity projections - which can be acquired very rapidly are sufficient: to get a correct diagnosis.