Volumetric study of the olfactory bulb in patients with chronic rhinonasal sinusitis using MRI

Olfaction plays an important role in human daily life. The olfactory bulb size is dependent on stimulation. Smell loss is one of the main symptoms in chronic rhinonasal sinusitis. MRI has been indicated to evaluate the size of the olfactory bulb in such patients. The aim of this study was to assess the volumetric changes of the olfactory bulb in patients with sinonasal polyposis before and after treatment using MRI. Fifteen control subjects and 30 patients were included in the study, 24 of them patients underwent endoscopic sinus surgery. Volumetric analysis of their olfactory bulb volume was done using MRI and specialized software. It was found that the olfactory bulb volume was significantly smaller in patients (19.98±5.88mm3) when compared to control mean (39.6±13.8mm3) and there was a significant increase in the olfactory bulb volumes in patients who underwent surgery 6months postoperatively (24.79±5.11mm3). MRI with volumetric analysis is a useful tool in assessment of the olfactory bulb volume in patients with olfactory loss and appears to be of help in assessment of the degree of recovery in patients after sinus surgery.