Evaluation of the Relationship Between Sphenoid Sinus Morphology and Area and Volume by Computed Tomography

Purpose: The aim of this retrospective study is to evaluate the relationship between sphenoid sinus volume and surface area measurements and its morphology by computed tomography (CT). Methods In this study, CT images of 150 patients were evaluated retrospectively. Sphenoid sinus pneumatization types, Onodi cell (OC) prevalence, protrusion and dehiscence of internal carotid artery (ICA) and optic nerve (ON) were evaluated. The volume and area of the sphenoid sinus were calculated using the manual segmentation module using InVesalius software program. Results Out of the 150 sinuses, 58 (38.66%), 47 (31.33%), 22 (33%), 4 (2.66%) and 8 (5.33%) were postsellar a, postsellarb,sellar type,conchal and presellar type, respectively. OC was found in 43 (28.7%) of 150 patients. ICA protrusion was observed in a total of 61 CTs (40.7%), 23 (15.3%) were unilateral and 38 (25.3%) were bilateral. Out of 61 CTs (40.7%) who showed ICA dehiscence, 51 (34.0%) were unilateral, and 10 (6.7%) were bilateral. ON protrusion was observed in a total of 43 CTs (28.7%), 14 (9.3%) were unilateral and 29 (19.3%) were bilateral. Out of 28 CTs (18.7%) who showed ON dehiscence, 17 (11.3%) were unilateral, and 11 (7.3%) were bilateral. The mean volume and area of sinus were 9949.4 ± 351.0 mm 3 and 4570.9 ± 1604.9 mm 2 , respectively. Conclusions Sinus volume and area were significantly higher in patients with bilateral protrusion of ICA compared to patients without protrusion of ICA. In patients with bilateral dehiscence of ICA, sinus volume and area were found to be significantly higher than those without ICA dehiscence. Sinus volume and area were significantly higher in patients with bilateral protrusion of ON compared to patients without ON protrusion. Sinus volume and area in males were found to be significantly higher than in females.There was a negative correlation between age and sinus volume and area.Sphenoid sinuses are in different variations with the important surrounding neurovascular structures. It is important to examine these relationships in detail before the operation in order to prevent complications.