Computed Tomography Scans in the Evaluation of Patients with Olfactory Dysfunction

Abstract
Background: The necessity of computed tomography (CT) scans of the olfactory cleft and the sinuses in patients presenting with olfactory dysfunction is a matter of debate. This study aimed to investigate the significance of CT scans for the diagnosis of olfactory loss and for therapeutic decisions. Methods: This retrospective study included 137 consecutive patients presenting with the main complaint of olfactory loss. Standardized history; ear, nose, and throat examination; and olfactory tests were administered. In addition, a CT scan of the nasal sinuses was obtained. The assumed diagnosis (sinonasal disease [SND] or non-SND) was compared with the diagnosis when additionally considering results from the CT scan. Results: CT scans suggested SND in 7/101 patients without clinical evidence of its presence. In 12/36 patients with suspected SND-related olfactory loss, no signs of SND were detected in CT scans. Conclusion: CT scans are useful to diagnose conductive/inflammatory olfactory loss in patients suspected of non-SND, which may then justify a course with systemic steroids. Alternatively, considering low costs and rare side effects of a short course with steroids in selected patients, CT scans appear to be of clinical significance only when surgical treatment is contemplated or where the use of systemic corticosteroids is not possible.