A COMPARATIVE STUDY OF CT AND SECTIONAL ANATOMY OF SPHENOID SINUS

Objective To study the difference between CT pictures and anatomy of sphenoid sinus and provide the information for sinus operation. MethodsBy means of CT scanning and anatomic sectioning, the shape, type, diameter and syntopy of the sphenoid sinus were observed in 15 adult cadaveric head and 50 skull specimens. ResultsThe anteroposterior diameter (A-PD) of the sinus was longer than its superoinferior diameter (S-ID); the superior and anterior walls (S-AW) were thinner than the inferior and posterior. The type of pneumatization, superior and posterior walls, lateral walls, the location of septum and its thickness and adjacent were clearly appeared on CT. On coronal scan, both the thickness of superior and inferior walls and the relationship between superior wall and hypophysis, internal carotid artery could also be seen. The bulges of the optic canal (23.5%) and the internal carotid artery (21.9%) can be found within the sinus, the former could only be seen in well-pneumatized antero-sellar and pansellar types. The posterior walls were thinner, the thinnest being 0.6 mm. ConclusionThe variation of the pneumatization of sphenoid sinus is big. The optic nerve, internal carotid artery may intrude into the sinus. A well-developed occipit-sellar or pan-sellar sinus is separated from brain stem by paper-thin bone plate. A great attention should be paid in transphenoidal approach surgery not to damage the surrounding structures.