[Study of variations in adult sphenoid sinus by multislice spiral computed tomography]

Explore the anatomic variations of adult sphenoid sinus and delineate the precise relationship between sphenoid sinus and adjacent structures.

Using multi planner reformation (MPR), the images of 260 spiral computed tomography (CT) scans were reviewed through a doctor station.

The sphenoid was divided into 6 types: no development, conchal, pre-sellar, half-sellar, full-sellar and post-sellar. The prevalence was 0.19%, 1.54%, 8.08%, 22.88%, 20.58% and 46.73% respectively. And there was no difference between left and right. The prevalence of accessory septa or bone spur inside sphenoid sinus was 51.5%. With the gasification spreading, the prevalence was rising. And there was statistical significance among them. The dorsum sella was divided into three types: I, II, III. And its prevalence was 48.08%, 25.19% and 26.73% respectively. The difference of sphenoethmoid distribution among the various type sinus had no statistical significance. The prevalence of vidian canal and foramen rotundum protrusion was 39.2% and 15.8% respectively. And all occurred in pterygoid process cells. Internal carotid artery (ICA) was divided into 4 types. And the prevalence of type 0 to 3 was 13.5%, 50.0%, 26.9% and 9.6% respectively. With the gasification spreading, the prevalence of types 2, 3 was rising. And there were statistical significance among them. The prevalence of type 0 to 4 CNII was 4.4%, 19.2%, 26.0%, 29.0% and 21.4% respectively. With the gasification spreading, the prevalence of type 3, 4 CNII was rising. And the difference had statistical significance.

MPR and multislice spiral CT can facilitate a precise study of anatomic variations in adult sphenoid sinus and delineate the relationships between sphenoid sinus and adjacent structures. Caution must be exercised during sphenoid and trans-sphenoid surgery to minimize the risk of inadvertently injuring the adjacent structures.