Measure The Volume Of Olfactory Bulbs By Mri And Study The Correlation Of Olfactory Function And Olfactory Bulb In Post-traumatic And Post-infectious Patients

Objective: To measure the volume of olfactory bulbs of the patients with olfactory dysfunction after head injury and upper respiratory tract infection ,and discuss the relationship between the volume of olfactory bulbs and olfactory function .Methods: 27 participants with post-traumatic olfactory deficit and 25 patients with post-infectious olfactory deficit were selected in the studies,who underwent olfactory function test and 3D-MRI scan as the case group.52 patients ,29 were male(trauma 20;infection 9)and 23 were female(trauma 7;infection 16);Age 20～68 years old (average 45±13.23 years old), the inspected course (from being found olfactory dysfunction after head injury and upper respiratory tract infection to being inspected) 1～48 months (median 9.80±11.21 months). 22 examples in the patient group reexamined after 2～6 monthes. 50 age-matched volunteers(M 27,F 23 ; age 20～66 ,average 44±13.10)with normal olfactory as the control group underwent olfactory function test and 3D-MRI scan too.All tested persons judge of olfactory functions by Sniffin' Sticks,involving odor threshold-T, odor discrimination-D, and odor identification-I, which are collectively called TDI scores. MRI data acquisited through sagittal plane three-dimensional fast spoiled gradient-recalled sequence(3D-FSPGR). to segregate the olfactory bulbs(OB) from the olfactory bundle(OT) by the"sudden",Volumetric measurement of the olfactory bulbs was performed by manual segmentation of the consecutive and being added. To compare the olfactory bulbs volums and olfactory function in the patient group with the control group by statistical methods,and analysis the relationship between the volume of olfactory bulbs and olfactory function.Results: In the control group, olfactory bulbs volume saverage value in left side 63.30±13.55 mm~3 ; olfactory bulbs volume saverage value in right side 65.45±14.98 mm~3. There was no significant difference between the male or female in olfactory bulbs volume (left t=1.34; p=0.19; Right t=0.78; p=0.44).the side olfactory function of patients with olfactory dysfunction after the unilateral nose or frontal lobe injury were lower than the healthy side, simultaneously, the wounded side accompanied with smaller olfactory bulbs volums than the healthy side(the affected side average 37.21±8.83 mm~3;the opposite side average 46.35±9.39 mm~3;t=-3.52;p=0.008).The volume of olfactory bulbs in post-infectious patients were smaller than controls(left t=-8.60;p<0.05;right t=-7.70;p<0.05).The two side olfactory function and olfactory bulb volums in post-infectious patients were not different(olfactory function t=-1.24;p=0.23;olfactory bulb volum t=-1.65;p=0.11). patients of anosmia in the patient group accompanied with smaller olfactory bulbs volums than hyposmia(the wounded patients t=-3.84;p<0.05;the infected patients t=-4.13;p<0.05).7 cases (7/22) olfactory function improved in 22 cases of review patients with olfactory function increases,in which 5 patients olfactory bulb volums became larger(first left olfactory bulb volums 25.00±13.09 mm~3;review 42.74±14.59 mm~3;first right olfactory bulb volums 37.82±12.97 mm~3;review 46.04±6.12 mm~3.).Conclusion:1.In the control group,there was no significant difference between the male or female,the left side or the right side in olfactory bulbs volume and olfactory function.the olfactory bulb volumes decreased with age.2.The side olfactory function of patients with olfactory dysfunction after the unilateral nose or frontal lobe injury were lower than the healthy side, simultaneously, the wounded side accompanied with smaller olfactory bulbs volums than the healthy side.the MRI manifestation of olfactory bulbs,olfactory tracts after injury:the normal olfactory bulbs dispeared and the signal was inhomogeneous.3.The upper respiratory tract infection can cause olfactory disfunction abruptly,vast majority bilateral.the MRI manifest that the normal olfactory bulbs appearance existed,the signal was lower,inhomogeneous or normal.4.In the patient group,there was no significant difference between the left side or the right side in olfactory bulbs volume.the volume of olfactory bulbs were smaller than controls,patients of anosmia accompanied with smaller olfactory bulbs volums than hyposmia.5.The olfactory function increases with larger olfactory bulb volume.6.The olfactory bulb volume in patients with damaged peripheral olfactory structures were correlated with olfactory function .Reduced olfactory bulb volume may be considerded to be characteristic of parosmia , simultaneously, the olfactory bulb volums may be one of olfactory function prognostic indicators.