Olfactory Dysfunction in Nasal Polyposis: Correlation with Computed Tomography Findings

Abstract
This study evaluates if a computed tomography (CT) scan is useful to assess the olfactory loss in sinonasal disease, and if a preoperative CT scan has a predictive value for the long-term outcome regarding olfaction. Thirty-one patients with nasal polyposis were included. Olfactory function was assessed with the 'Sniffin' Sticks' test and subjective perception recorded with a visual analogue scale. CT scans were assessed with the Lund-Mackay system and the Damm nasal segmentation. Patients were retested after endoscopic sinus surgery in a follow-up appointment at least 1 year later. Disease in the upper meatus and the posterior portion of the middle meatus strongly affects olfactory function. Lund-Mackay scores were significantly correlated with preoperative olfactory test results. Preoperative subjective ratings had a significant correlation only with present disease in the anterior upper meatus. Postoperative results were significantly decreased. Their relative percentage change was correlated only with the preoperative presence of disease in the anterior upper meatus. No correlation was found between the Lund-Mackay score and the postoperative olfactory results. Olfactory dysfunction in nasal polyposis is strongly related to specific obstructed nasal areas. A CT scan has no predictive value for the long-term surgical outcome regarding olfaction.