Navigation in neuroendoscopy

Navigation in neuroendoscopy is becoming increasingly important, especially in complex interventions, such as tumour biopsies and cyst fenestrations. Theoretically, all existing image modalities are available to fulfill this need. Navigation with preoperative computed tomography (CT) or magnetic res onance images represents the 'gold standard' and is highly recommended for almost all neuroendoscopic operations. However, intra-operative changes of anatomy, due to, e.g. brain shift, cannot be taken into account by such nav igation systems. For such cases, real-time imaging with sonography, CT or M RI may be helpful. At the moment, these methods are not routinely employed. Another interesting future development is digital image-processing in neur oendoscopy (as well as in other endoscopic procedures). With this new metho d, the control of dangerous intra-operative situations may become easier (b ecause different modules are available) and documentation and training can be performed using the stored digital endoscopic images. This article gives an overview of the different existing navigational methods in neuroendosco py.