The Study Of MRS And DTI In Parkinson's Disease

Objective:To investigate the clinical value of proton magnetic resonance spectroscopy ('H-MRS) and diffusion tensor imaging (DTI) in diagnosing idiopathic Parkinson's disease (PD) based on the conventional magnetic resonance imaging (MRI).Material and Methods:27 PD patients were selected as study group and 27 normal ones which matched to PD patients in terms of age, sex and extent of education were selected as control group. PD patients were divided into early stage and advanced stage according to Hoehn & Yahr grading. Levels more than 2.5 were defined as advanced stage, or were defined as early stage. According to the third Version Unified Parkinson's Disease Rating Scale (UPDRS-III), higher scores in PD group with bilateral limb symptoms were defined as symptoms of a serious side. Conventional MR], MRS and DTI scans were performed in all subjects. Then NAA, Cho, Cr, NAA/Cho, NAA/Cr and Cho/Cr of bilateral putamen were measured and analyzed. At the same time, changes of fractional anisotropy (FA) and average apparent diffusion coefficient (ADC) of bilateral substantia nigra, thalamus, caudate nucleus and putamen were analyzed.Results:(1) No statistical difference between PD group and control group were found on conventional MRI. (2) The values of NAA, Cho, Cr, and ratios of NAA/Cr, Cho/Cr in left Putamen were lower than those of right putamen in control group (P< 0.05). According to the S-N-K inspection (a=0.05). the NAA, Cho and Cr of bilateral putamen in early PD group and advanced PD group were higher than those in control group. But there was no statistical difference between the first two groups. And there was no statistical difference of NAA/Cho, NAA/Cr and Cho/Cr among the three groups too. All the metabolites and their ratios were not significant different in the ipsilateral and contralateral side of the putamen with severe symptoms in early PD group and advanced PD group. NAA, Cho, Cr and Cho/Cr of bilateral putamen in PD group were significantly higher than those in the control group, but NAA/Cho in PD group was lower than that in control group (P< 0.05). (3) The FA values of left caudate nucleus and lenticular nucleus, ADC values of left substantia nigra were higher than those of right side in control group (P< 0.05). According to the S-N-K inspection (a=0.05), the FA values of bilateral substantia nigra, lenticular nucleus, thalamusin in advanced PD group were lower than those in early PD group and control group. ADC values of lenticular nucleus in advanced PD group were higher than those in early PD group and control group, but there was no statistical difference between the latter two groups(P< 0.05). There was no statistical significant difference in FA value and ADC value in both ipsilateral and contralateral interest regions (the substantia nigra, putamen, thalamus, caudate nucleus) between early PD group and advanced PD group.Conclusion:(1)Conventional MRI makes little contribution to diagnosis of PD.(2)Bilateral putamen MRS (NAA, Cho, Cr, Cho/Cr and NAA/Cho) contributes to diagnosis of PD, but it doesn't contribute to the assessment of disease severity in PD patients with bilateral limb symptoms.(3) Bilateral substantia nigra, thalamus and putamen FA values make some help in diagnosis and severity assessment in advanced PD patients, but there is little help in early diagnosis of PD and in the severity assessment in patients with bilateral limb symptoms.