OBJECTIVETo analyze the correlation between olfactory bulb (OB) volume, depth of olfactory sulcus (OS) and olfactory function in patients with olfactory dysfunction after upper respiratory tract infection.

METHODSOne hundred patients with olfactory dysfunction after upper respiratory tract infection (patient group) were compared with one hundred normal controls in terms of olfactory function T&T testing, OB volume and depth of OS assessed with magnetic resonance imaging (MRI). T&T testing and MRI were performed again after a year in patient group and the results were compared. SPSS 13.0 software was used to analyze the data.

RESULTST&T olfactory testing revealed that the patient group had higher scores than controls (t = 4.014, P < 0.05). Both men and women in patient group were affected by the same extent of olfactory loss (t value was 0.892, P > 0.05). Both men and women in control group were affected by the same extent of olfactory loss (t value was 1.011, P > 0.05). OB volume of left side in patient group was (38.14 ± 4.31) mm³, right side was (38.72 ± 4.22) mm³, average OB volume was (38.47 ± 4.27) mm³; OB volume of left side in controls was (51.65 ± 6.30) mm³, right side was (51.98 ± 6.34) mm³, average OB volume was (51.81 ± 6.32) mm³; OB volume was lower in patient group as compared with controls (t value were 4.233, 4.267 and 4.249, all P < 0.01). OS depth study revealed no statistical difference between patient group and control group (t value were 0.901, 0.948 and 0.927, all P > 0.05). Olfactory discriminate threshold was negatively correlated with OB volume in patient group and control group (r value were -0.598, -0.512, both P < 0.05) Olfactory discriminate threshold was not correlated with the depth of OS (r value were -0.152, -0.174, both P > 0.05). Olfactory discriminate threshold and OB volume were not correlated with the persistent time of the dysosmia in patient group (r value were -0.121, 0.139, both P > 0.05). Among 100 olfactory dysfunction patients after upper respiratory tract infection, when followed-up, 24 showed increased in OB volume and olfactory function after a year, but no statistical difference was found with the first time (t value were 0.894, 0.914, 0.942 and 0.931, all P > 0.05). The other 76 patients showed no significant changes of OB volume and olfactory function.

CONCLUSIONSThe OB volume was lower in patient group as compared with normal controls, the depth of OS showed no significant changes in patient group. The OB volume was correlated with olfactory function, the depth of OS was not correlated with olfactory function; Olfactory function had not correlated with the persistent time of the dysosmia in patient group.