Utility of magnetic resonance imaging in idiopathic olfactory dysfunction: structural findings and functional correlation
DOI:
https://doi.org/10.34631/sporl.3231Keywords:
olfactory dysfunction, olfactory bulb, Magnetic resonance imaging, smell, anosmiaAbstract
Objectives: To characterize magnetic resonance imaging (MRI) findings in patients with suspected idiopathic olfactory dysfunction (IOD) and evaluate the correlation between olfactory bulb (OB) volume and olfactory function.
Study Design: Retrospective cross-sectional study.
Material and Methods: Sixty-one patients with IOD evaluated between 2018 and 2025 were included. Olfactory function was assessed using the Portuguese Smell Test. MRI of the olfactory tract was used for OB volumetric assessment and characterization of structural findings. Correlations between OB volume and olfactory function were analyzed using Spearman’s coefficient.
Results: OB atrophy was the most frequent imaging finding (60.6%). MRI identified a specific underlying cause in 3.3% of cases. A positive trend was observed between mean OB volume and DIF score, without statistical significance (ρ=0.296; p=0.051).
Conclusions: MRI remains relevant in the evaluation of IOD, allowing identification of specific causes in selected cases. The absence of a significant correlation between OB volume and olfactory function reinforces the pathophysiological heterogeneity of IOD.
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Copyright (c) 2026 Rafael Pires, Vera Vaz Teixeira, Ricardo Nelas, Jorge Dentinho, Aldora Quintal, Mário Santos, Luís Antunes
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