Compared research between CT and sectional anatomy of sphenoid sinus

Objective: To provide the data of both anatomic and medical imaging for transphenidal sinus operations. Methods: By means of CT scanning and anatomic sectional ways, the shape, type, diameter and syntopy of the sphenoid sinus were observed in 15 adult cadaveric head specimens and 50 dry skull specimens. Results: The anteroposterior diameter of sphenoid sinus was longer than its superoinferior diameter; the superior and anterior walls were thinner than the inferior and posterior walls. On axial CT sections, the types of pneumatization of the sphenoid sinus was clearly shown, as well as the position, thickness and syntopy of its septum and walls which excluded the superior and inferior ones. Both the thickness of superior and inferior walls and the relationship between superior wall and hypophysis, internal carotid artery could also be seen on coronal CT sections. The Bulges of the optic canal (23. 5%) and the internal carotid artery (21. 9%) can be found within the sphenoid sinus, the former of the optic canal can only be found in the cases of the well-pneumatized antero-sellar and pansellar types. The posterior walls of the well-pneuma-tized sphenoid sinuses were thinner in occipit-sellar and pansellar types, and the thinnest of them was only 0. 6 mm. Conclusions: The variation of the sphenoid sinus is very obvious. The optic canal and internal can-rotid artery could protrude into sinus. There is only one thin ostero-plate between brain stem and sphenoid sinus in developed occipit-sellar and pansellar typical sinuses. The operative field of transphenoidal sinus should bye confined to avoid damaging neighboring structures.