A Preliminary Study On The Application Of Amide Proton Transfer Imaging In Parkinson's Disease

Background and objective:Parkinson's disease(PD)is a neurodegenerative disease that occurs in the middle and old age.The main pathological change is the degeneration and disappearance of dopaminergic neurons and the formation of Lewy bodies.The main physiological change is a decrease in striatal dopamine transmitters.The prevalence of Parkinson's disease in people over 65 years old in China is about 1.7%,and it increases with age.Imaging examination is an indispensable part of the diagnosis and differential diagnosis of PD and related dyskinesia diseases.However,the information reflected by conventional magnetic resonance imaging is limited.Therefore,new techniques of MRI are needed to reflect more abundant information from different perspectives.Amide proton transfer(APT)MR imaging is a non-invasive magnetic resonance molecular imaging method based on chemical exchange saturation transfer technology.The APT weighted(APTw)signal intensity generated by APT magnetic resonance imaging can reflect the content of endogenous free proteins and peptides in biological tissues and the exchange rate of amino protons,so that the reaction indirectly reflects metabolic changes and physiological and pathological information inside living cells.The typical pathological manifestation of Parkinson's disease is the formation of Lewy bodies,while the main component of Lewy bodies is abnormally aggregated ?-synuclein.This article aims to explore the value of using APT MRI in the diagnosis of Parkinson's disease.Materials and Methods:Twenty-two patients with Parkinson's disease(patient group)and 18 gender-and age-matched healthy controls(healthy control group)were enrolled.Patients were divided into early stage PD group(1-2 points)and advanced stage PD group(2.5-4 points)according to Hoehn-Yahr score.Regular MRI,Susceptibility Weighted Imaging(SWI)and APT MRI scans were performed on all enrolled subjects.The data was analyzed using a Siemens workstation(Syngo MR B17,Siemens).Referring to the corresponding level of SWI images,the region of interest(ROI)is delineated on the APT image for the substantia nigra,red nucleus,caudate nucleus,globus pallidus and putamen,and the magnetic resonance ratio asymmetry at 3.5 ppm of these brain structures is measured.The data were analyzed by SPSS 22.0 statistical software.The difference of MTRasym(3.5 ppm)of these cerebral structures between the PD patients and the healthy controls was compared by the independent sample t test.The paired-sample test was used to compare the difference of MTRasym(3.5 ppm)between the onset and contralateral brain structures of the PD patients.One-way ANOVA was used to compare the differences in brain structure MTRasym(3.5 ppm)between healthy controls and patients with different degrees of PD.The LSD-t test was used to compare the two groups.The difference was statistically significant at P < 0.05.Results:1.There were no significant abnormalities in routine magnetic resonance imaging in all subjects enrolled.2.Compared with the healthy control group,the MTRasym(3.5 ppm)of the substantia nigra in patients with Parkinson's disease decreased,and the difference was statistically significant(t=-7.763,P(27)0.05);the MTRasym(3.5 ppm)of the red nucleus decreased.However,the difference was not statistically significant(t=-1.443,P>0.05);the MTRasym(3.5 ppm)of globus pallidus,putamen and caudate nucleus increased,and the difference was statistically significant(t=2.880,P(27)0.05;t = 3.616,P(27)0.05;t = 3.823,P(27)0.05,respectively).3.The MTRasym(3.5 ppm)of sides of onset of substantia nigra,red nucleus,putamen,globus pallidus and caudate nucleus in patients with Parkinson's disease decreased slightly compared with the contralateral side,but the difference was not statistically significant(P >0.05).4.One-way ANOVA showed that there was a statistically significant difference in the MTRasym(3.5 ppm)among the healthy controls,the early and advanced stage Parkinson's disease patients(F=44.094,P(27)0.001),and the differences between the two groups also showed a statistically significance(P(27)0.01);The MTRasym(3.5 ppm)of the red nucleus gradually decreased with the progression of the disease,but the difference was not statistically significant(F=1.154,P=0.327);There were significant differences in MTRasym(3.5 ppm)of the globus pallidus,the putamen and the caudate nucleus among the healthy controls,the early and advanced stage PD patients(F=8.107,P=0.001;F=6.587,P=0.004;F=7.442,P= 0.002);The MTRasym(3.5 ppm)of globus pallidus,putamen and caudate nucleus in the early and advanced stage group were higher than that in the control group,and the difference was statistically significant(P(27)0.01);The MTRasym(3.5 ppm)of globus pallidus,putamen and caudate nucleus in the early stage group was higher than that in the advanced stage group,but the difference was not statistically significant.Conclusion:As a new non-invasive magnetic resonance imaging method,APT MR imaging can provide some help for the clinical diagnosis of Parkinson's disease by measuring the MTRasym(3.5 ppm)value of the corresponding brain structure.