[Imaging study of anatomical parameters related to pterygoid canal neurotomy].

Measuring the important anatomic parameters related to vidian neurectomy to locate the vidian nerve accurately and prevent the surgical complications. High resolution CT（HRCT） was used to measure the distance parameters between the important anatomic landmarks in 50 patients （100 sides） with chronic rhinosinusitis, sinus cyst or allergic rhinitis et al. The distance from the posterior opening of the palatovaginal canal to the upper edge of the sphenoidal process of palatine bone, the upper edge of the sphenoidal process of palatine bone to the external opening of the vidian canal, the external opening of the vidian canal to the greater palatine canal, and the external opening of the vidian canal to the foramen rotundus were measured. The posterior opening of the palatovaginal canal, the upper edge of the sphenoidal process of palatine bone, the external opening of the vidian canal, the greater palatine canal, and the foramen rotundum are of great value in locating vidain nerve and preventing surgical complications. The distance from the posterior opening of the palatovaginal canal to the upper edge of the sphenoidal process of palatine bone, the upper edge of the sphenoidal process of palatine bone to the external opening of the vidian canal, the external opening of the vidian canal to the greater palatine canal, and the external opening of the vidian canal to the foramen rotundus were（12.46±1.19） mm, （3.23±0.36） mm, （6.09±0.75） mm and（7.6±1.16） mm respectively. HRCT can be used as a powerful tool for preoperative localization of the external pterygoid nerve orifice and its related important anatomical landmarks, and the preoperative distance parameters obtained are valuable for intraoperative localization of the pterygoid nerve to prevent the occurrence of complications.