ANATOMICAL VARIATIONS OF NASAL CAVITY AND PARANASAL SINUSES IN SINUSITIS ON CT-SCAN

Abstract

Enhancements in functional endoscopic sinus surgery (FESS) and computed tomography (CT) scans have concomitantly amplified interest in variation of the nasal cavity and paranasal sinus (PNS) region anatomy. Anatomical variations are normal morphological structures that are present in humans. The presence of these anatomical variations can affect nearby anatomical relations resulting in structural changes. By the vast range of anatomical variations in nasal cavity and paranasal sinuses, every case of sinusitis must be planned carefully to avoid complications in surgical procedures. Certain anatomical variants are supposed to be a causative factor for development of sinus pathology and hence it should be compulsory for the radiologist to be aware of the anatomical variants of nasal cavity and PNS especially if the subject is considered for surgical intervention. CT Scan imaging of nose and PNS is mandatory in patients with history of sinusitis in order to evaluate the detailed anatomy which includes normal morphology, anatomical variations, bony details and the extent of the disease pathology. The objectives of this study were to determine the incidence of sinonasal anatomic variants in symptomatic subjects of sinusitis on CT-scan, and to evaluate the association between gender, symptoms and anatomical variations of sinonasal region in symptomatic subjects of sinusitis on CT-scan. A cross-sectional study including 80 subjects was conducted at PNS Shifa Hospital, Karachi between January-June 2020. The study involved males and females with age ranges from 18-60 years. Subjects were prepared for CT Scan of PNS in coronal and axial view. Study included subjects symptomatic for sinusitis irrespective of gender associated with headache, nasal obstruction, facial pain, rhinorrhea and sinus mucosal thickening of greater than 1 mm. The scans were reviewed to study the nasal septum, turbinates, uncinate process, ethmoid air cells, hypoplastic frontal sinus, maxillary septa, asymmetry of sphenoid sinus cavity and all these anatomical variants were correlated with symptoms of sinusitis. The results of this study showed that there were more males (53) as compared to females (27) with mean age of 44.6±18.5 years who were suffering from sinusitis, headache being the most frequent symptom followed by nasal obstruction, rhinorrhea and facial pain with reported frequencies of (48.75%), (26.25%), (18.75%) and (6.25%) respectively. The anatomical variations were prevalent as 100% in x symptomatic subjects of sinusitis with significant number found in male gender. The most frequent anatomical variants were deviated nasal septum (DNS) (58.5%) followed by agger nasi cells (56.3%), concha bullosa (CB) (46.3), septal bony spur (40%), hypoplastic frontal sinus (31.3%), asymmetry of both cavities of the sphenoid sinus (18.8%), onodi cells (12.5%), haller cells (11.3%), uncinate process deviation (2.5%) and pneumatization (3.8%), superior CB (1.3%), paradoxical middle CB (1.3%), and maxillary septa (1.3%). It was noticed that only nasal obstruction and headache were associated with agger nasi cells right and left sides both with significant p-values of 0.014 and 0.026 respectively. Moreover, insignificant association was found between gender, anatomical variants and symptoms of sinusitis.