Reasearch Of MRI On The Olfactory Associated Brain Areas Of Patients With Pakinson’s Disease

Part I ADC value assessment of change of function in olfactoryassociated brain areas of Parkinson’s disease by MRIdiffusion-weighted imagingObjective: To analyze the change of apparent diffusion coefficient(ADC values) in olfactory associated brain areas of patients with Parkinson’s disease(PD) and olfactory dysfunction, and to analyze the correlation between substantia nigra and olfactory associated brain areas by using magnetic resonance diffusion-weighted imaging(DWI), in order to evaluate clinical application on assessment of olfactory function and early diagnosis of Parkinson’s disease by DWI.Methods: PD group included 35 cases of patients,and control group included 35 cases of healthy volunteers with matched age and sex, furthermore, all of PD patients had olfactory dysfunction with different level. All patients and controls were scanned using DWI sequence with 16 channel head/neck coil, and were measured and caculated for the ADC values in olfactory associated brain areas(gyrus rectus,orbital recus,PCA,hippocampus and parahippocampal gyrus)and substantia nigra, among them, PCA represented piriform cortex and the amygdale. the contrastive analysis of the ADC values of every ROI area was performed between the two groups, and the correlation anaysis was performed between the ADC values of PD patients in olfactory associated areas and in sunstantia nigra, as well as, the correlation anaysis was performed between the ADC values of PD patients in olfactory associated areas and HY grades.Result: The ADC values in gyrus rectus、PCA and substantia nigra of PD patients were all greater than the ADC values in corresponding areas of controls, and there were statistically significant different between the two groups(t:2.306、10.097、2.262, P:0.023、0.000 、 0.025); and the other olfactory associated brain areas were of no statistically differences between two groups(P>0.05). The results of the correlation anaysis between substantia nigra and gyrus rectus 、between substantia nigra and PCA suggested that both of them had no conspicuous correlation(r: 0.146、0.203, P: 0.229、P=0.092).The contrastive analysis of the ADC values of PD patients in olfactory associated areas between HYI grade and HYII grade: the ADC values in gyrus rectus、hippocampus and parahippocampal gyrus of PD patients of HYII grade(0.778±0.099、0.871±0.084)were all greater than the ADC values in gyrus rectus、hippocampus and parahippocampal gyrus of PD patients of HYI grade(0.712 ±0.122、0.828±0.077), and the differences between the two groups were statistically significant(gyrus rectus:t=-2.480 、 p=0.016;hippocampus and parahippocampal gyrus:t=-2.242、p=0.028); however, the ADC values in orbital recus、PCA were of no statistically differences(p>0.05).Conclusion: the ADC values of PD patients in gyrus rectus、PCA had increased, and the change of ADC values had correlation with states of the disease, The analysis of ADC values in olfactory associated areas can help to diagnose PD at early stage and evaluate the state of the disease.Part II The value of T2 value assemment of iron content in olfactory associated brain areas and olfactory function of Parkinson’s disease byMRI double echo sequenceObjective: To measure the T2 values in olfactory associated brain areas of patients with Parkinson’s disease using magnetic resonance double echo sequence, and evaluate change of iron content in related brain areas and the correlation between it and change of olfactory function, so as to explore the clinical application of T2 values using magnetic resonance double echo sequence on evaluating iron content and olfactory dysfunction of PD.Methods: The PD group included 29 cases of patients at early stage, and the controlgroup included 33 cases of healthy volunteers with matched age and sex. All of PD patients and controls were performed for olfactory detection. patients and controls were scanned using dual echo sequence with 16 channel head/neck coil, and images were processed using the special software, then all subjects were measured for the T2 values and iron content in olfactory associated brain areas(gyrus rectus, orbital recus, PCA, hippocampus and parahippocampal gyrus), and we statistically analyzed the change of T2 values and iron content in every olfactory associated area of PD patients and control patients, and the correlation between the change and olfaction function、states of the disease.Result: The result of olfactory detection found that among 29 cases of PD patients there were 12 cases had euosmia and 17 cases had hyposmia and no one had anosmia,therefore 33 cases of controls all had not olfactory dysfunction. The T2 values in left、right side of olfactory associated areas of PD group and control group were of no statistically differences(p>0.05). The T2 values in PCA and hippocampus and parahippocampal gyrus were statistically different between PD group and control group(t:-3.725、-2.265, P: 0.000、0.025), and the T2 values showed increases in PCA、hippocampus and parahippocampal gyrus of PD group with comparison of normal control group. The T2 values in gyrus rectus 、 orbital recus between two groups had no statistical difference(p>0.05). The T2 values in all olfactory associated areas between HYI grade and HYII grade were not stastically different(p>0.05). The difference between the T2 values in all olfaction-related areas of PD patients with normal olfactory function and it of PD patients with decreased olfactory function was not conspicuous(p>0.05).Conclusion: The double echo sequence can help to evaluate iron content of Parkinson’s disease in olfactory associated brain areas. The T2 values of PD patients in PCA、hippocampus and parahippocampal gyrus were lower than controls, it suggested iron content in olfaction-related areas of PD group has increased, but the change have no correlation with the stages of disease and olfactory function.Part III Clinical application on evaluation of chage of FA values inolfactory associated brain areas of Parkinson’s disease by MRIdiffusion tensor imagingObjective: To analyze the change of FA values in olfactory associated brain areas and substantia nigra of patients with Parkinson’s disease(PD) and the correlation between them and to analyze the change of fibers by magnetic resonance diffusion tensor imaging, for the purpose of discussing clinical application of FA values on evaluate olfactory function of Parkinson’s disease.Methods: PD group includes 34 cases of patients with olfactory dysfunction, control group includes 44 cases of healthy volunteers with matched age and sex. PD patients and controls were scanned using DTI axial sequence with 15 directions, every subject was measured for the FA values in olfaction-related areas(gyrus rectus,orbital recus,PCA,hippocampus and parahippocampal gyrus) and substantia nigra, and generated fibrous scattered imaging. The FA values’ s comparison beween left and right sides of olfactory associated brain areas and substantia nigra between PD group and control group used paired samples t Test; The comparison of FA values in olfactory associated brain areas and substantia nigra between PD and controls、The comparison of FA values of PD patients in olfactory associated areas between HYI grade and HYII grade used two independent samples t test; The correlations of FA values between substantia nigra and olfactory associated areas were analyzed using two variable correlation analysis.Result: There was no statistically significant difference of FA values beween left and right sides of olfactory associated brain areas and substantia nigra of PD group and control group. The FA values in gyrus rectus(FA: 0.488±0.064, 0.691±0.068) 、hippocampus and parahippocampal gyrus(FA: 0.447± 0.045, 0.487± 0.154) and substantia nigra(FA:0.621 ± 0.097,0.691 ± 0.068) between PD and controls were statistically significant different(t:-20.472、-2.335、-2.972, P: 0.000、0.022、-0.043), and the FA values in gyrus rectus、hippocampus and parahippocampal gyrus、substantia nigra of PD patients were all lower than of controls, furthermore, the fibers of ROI of PD patients were fewer than controls. statistically, there were not conspicuous different between the FA values of PDpatients and controls in orbital recus and PCA(p>0.05). There was not definite correlation between substantia nigra and gyrus rectus、hippocampus and parahippocampal gyrus(P:0.974、0.074, r:-0.004,-0.016). in addition, there were not statistically different between the FA values of PD patients in HYI grade and in HYII grade(p>0.05).Conclusion: The FA values of PD patients in gyrus rectus 、 substantia nigra 、hippocampus and parahippocampal gyrus were lower than controls, and the fibers of PD patients were fewer than controls, in addition, there was no conspicuous correlation between substantia nigra and gyrus rectus、hippocampus and parahippocampal gyrus, and there was also no conspicuous correlation between gyrus rectus 、 hippocampus and parahippocampal gyrus and the stages of disease. magnetic resonance diffusion tensor imaging can evaluate the function in olfactory associated areas of PD patients with no injury, and has certain value for the eary diagnosis of PD.