Virtual imaging anatomy of transnasal approach to the clivus

Objective 　To observe the virtual anatomy via transnasal approach in a virtual-reality (VR) environment, and to establish a virtual anatomical model of clival region and explore the application value of the virtual-reality technology. Methods 　Twenty patients (males 11, females 9, aged from 25 to 70 years old with a mean of 43±0.3 years ) with no pathological changes in the sellar area and clivus underwent CT angiography with Discovery Ultra 16 and 3.0T MRI thin-slice scan. The data were collected and inputted into the Dextroscope in the DICOM format. Virtual observation of anatomy via transnasal approach and three-dimensional reconstruction of clivus were carried out in the VR environment. Results 　Virtual reconstruction and measurements of clivus were successfully performed in the 20 patients. The simulation of transnasal approach was also carried out in the VR environment. The lateral side of clival bone removal through transnasal approach was limited by internal carotid artery, the superior limit was sellar floor and the lower clivus could not be revealed completely because of the restriction of the maxilla and hard palate. Conclusions 　Virtual reconstruction of the clivus and simulation of transnasal approach can be performed exactly by VR technology, which provides imaginal and anatomical basis in dealing with clivus lesions via transnasal approach.