CT evaluation of congenital anatomical variations in paranasal sinuses

Introduction: A good knowledge of the anatomy of the paranasal sinuses is essential for the clinician to understand sinonasal diseases. Conventional radiology does not permit a detailed study of the nasal cavity and paranasal sinuses, and has now largely been replaced by computerized tomographic (CT) imaging. Currently, CT scanning is the standard imaging in the evaluation of the paranasal sinuses. Objective : To evaluate the congenital anatomical variations of paranasal sinus by CT scan. Materials and Methods: Over a period of 18months, 80 patients referred for CT scan of PNS region to Al-Ameen medical college hospital were evaluated for the presence of normal variants of the paranasal region. Unenhanced CT of the PNS was performed for these patients in the coronal plane, complemented by axial views in selected cases. Results: Deviated nasal septum was the most common variation in 72(90%) followed by concha bullosa in 31 (38.75%) patients. Other variations found were curved uncinate process in 16 (20%), hypoplastic frontal sinus in 14 (17.5%), overpneumatized ethmoidal bulla or giant bulla 13 (16.25%), Paradoxical middle turbinate in 12 (15%), prominent Agger Nasi cells in 11 (13.75%), superior concha bullosa in 07 (8.75%), ariated cristagali in 07(8.75%), haller cells in 05 (6.25%), onodi cells in 03 (3.75%), and pneumatization of uncinate process in 03 (3.75%) patients. Conclusion : The presence of anatomical variants does not indicate a predisposition to sinus pathology but these variations may predispose patients to increased risk of intraoperative complications. The radiologist must pay close attention to anatomical variants in the preoperative evaluation and provide a road map to the surgeon and help avoid possible complications and improve success of management strategies.