OBJECTIVETo use virtual endoscopy to obtain detailed three-dimensional images of bone, soft tissue and paranasal sinus damage as well as images of adjacent unaffected areas for optimum surgical planning.

METHODSA spiral CT scanner was used to examine 46 cases of facial bone fractures, maxillary cysts, obstructive sleep apnea syndrome (OSAS) and maxillary bone tumours. Data were input into a navigator workstation to create images similar to those displayed by a fiberoptic endoscope. Various 3-D images were obtained when probe sites were changed.

RESULTSVirtual endoscopy can clearly display the anatomic structure of the paranasal sinuses, nasopharyngeal cavity and upper respiratory tract, revealing damage to the sinus wall caused by a bone tumor or fracture. In addition, the technique can be used to indicate volume changes of the upper respiratory tract in OSAS patients. These results were similar to those obtained through actual operations.

CONCLUSIONSVirtual endoscopy is a new method which produces very clear images. It is reliable to provide detailed information for optimal operative planning.