Radiological Evaluation of Covid-19 Anosmic Patients By MRI of The Olfactory Bulb and Computed Tomography of the Paranasal Sinuses

Background: COVID-19 related olfactory dysfunction as an isolated symptom or in conjunction with other respiratory symptoms has been increasingly recognized. Aim: The aim of this study was to assess the olfactory cleft and the olfactory bulb in post COVID-19 anosmic patients with paranasal sinus CT, and MRI dedicated to olfactory bulb to detect possible mechanisms for post covid-19 olfactory dysfunction. Patients and Methods: This prospective study including 20 patients presented between 2021 and 2022 to Otorhinolaryngology Department at El-Hussein University Hospital & El-sahel Teaching Hospital. Results: In our study the mean right OBV (38.3 ± 12.03), the mean left OBV (35.6 ± 9.1), the mean right OSD (7.4 ± 0.83) & the mean left OSD (7.3 ± 0.9). As regard Primary olfactory cortex and visualized olfactory tracts, 19 patients (95%) were normal and 1 patient (5%) was abnormal (This patient showed bilateral asymmetrical increased signal intensity in FLAIR and T2 WIs within the primary olfactory cortices, more notable at the left side). As regard Nerve filiaa, 19 patients (95%) were normal and 1 patient (5%) was abnormal (This patient showed subtle thickening and clumped appearance of the left olfactory nerve filia). Conclusion: This study results showed high percentage of olfactory bulb degeneration suggests that injury to olfactory neuronal pathways also take place, specifically in cases with sub-acute and chronic post COVID-19 olfactory dysfunction. MRI can be used to demonstrate olfactory injury in patients with COVID-19 which allow the diagnosis and prognosis prediction in patients with OD so we recommend MRI imaging in cases of olfactory dysfunction.