# Anatomical Blueprint of the Sphenoid Sinus in Saudis: A Radiological Observational Perspective

## TL;DR

This study maps the anatomical variations of the sphenoid sinus in Saudi adults using CT scans, highlighting differences between men and women and the importance of preoperative imaging.

## Contribution

The study provides a detailed radiological analysis of sphenoid sinus anatomy in the Saudi population, emphasizing sex-related differences and proximity to critical structures.

## Key findings

- Males had significantly larger sphenoid sinus volumes compared to females.
- Post-sellar pneumatization was the most common pattern, with frequent extension into adjacent bony processes.
- Intra-sinus septation was present in nearly all cases, with sex-related differences in anatomical variants.

## Abstract

We analyzed computed tomography scans of 2433 adult Saudi patients to map variability in sphenoid sinus size, shape, and air-cell extension, and to examine its relationship with nearby critical structures, including the optic nerve and internal carotid artery. Most individuals had a deeply pneumatized “post-sellar” sphenoid sinus extending into adjacent bony processes, with almost all sinuses containing internal septa. Men and women showed differences in the sphenoid sinus and related important structures, which may protrude into the sinus or be partially uncovered. These findings underscore the importance of meticulous, CT-based preoperative assessment.

Background/Objectives: To evaluate and characterize anatomical variations in the sphenoid sinus in the Saudi population using computed tomography (CT). Methods: This retrospective cross-sectional study included patients aged ≥18 years who underwent multi-detector CT (MDCT) of the paranasal sinuses at King Fahd University Hospital between July 2018 and 2023 for different indications. Radiological variables analyzed included sphenoid sinus pneumatization type, presence and number of inter-sphenoid septa, and deviation or attachment to adjacent structures. Results: The data of 2433 patients were analyzed (44.5% males, 55.5% females; mean age 40 ± 15 years). The mean sphenoid sinus volume was 20.4 ± 8.7 cm3, significantly larger in males (p < 0.001). The most common sinus shape was quadrilateral (33%), whereas the predominant pneumatization pattern was post-sellar (57.1%), followed by sellar (32.1%), pre-sellar (9.2%), and conchal (1.6%). Adjacent-structure pneumatization was frequent, most notably in the greater wing of the sphenoid (47.4%) and pterygoid (39%) processes. Optic-canal protrusion and dehiscence were observed in 13.9% and 4.1%, respectively, whereas carotid canal protrusion occurred in 22.2% and dehiscence in 3.2%. Intra-sinus septation was identified in 97.7% of assessable cases, most commonly as a single septum (59.6%). Several variants showed significant sex-related associations, including sinus volume, anterior clinoid process/posterior clinoid process pneumatization, and dehiscence patterns. Conclusions: CT imaging revealed considerable diversity in the sphenoid-sinus anatomy among the Saudi population. Awareness of these variations, particularly their relationship with critical neurovascular structures, is crucial for radiologists and surgeons to ensure accurate diagnosis and safe surgical planning.