Study Of Diffusion Kurtosis Imaging In Parkinson’s Disease Patients By Voxel-based Analysis

Objective:Aimed to use diffusion kurtosis imaging(DKI)by voxel-based analysis to detect alterations in gray matter micro-structures in patients with Parkinson’s disease(PD),compared with healthy controls(HC),and analyze the quantitative parameters of DKI in different brain regions investigation of gray matter mirostructure changes in PD patients may contribute to understand the potential mechenism,and provide new ideas for the diagnosis.Materials and Method:(1)General information:50 PD patients diagnosed in the department of neurology of Northern Jiangsu People’s Hospital between March 2018 and September 2019 were collected,including 24 males and 26 females,aged 63.34±8.69 years;during the same period,35 healthy controls were collected matched in the age,gender and education level,including 18 males and 17 females,aged 60.28±6.52 years.(2)Date collection: All PD patients were tested with a clinically relevant scale,including the Mini-Mental State Examination(MMSE)、Montreal cognitive assessment scale(Mo CA)and unified Parkinson’s disease rating scale part III(UPDRS-III),as well as conventional brain magnetic resonance imaging(MRI)to eliminate organic lesions,including T1 WI,T2WI,fluid attenuated inversion recovery(FLAIR)sequence and diffusion weighted imaging(DWI);then,Ax DKI 30 Dir and 3D T1 BRAVO sequences were scanned.(3)Image preprocessing: DKI and 3D T1 BRAVO sequences were converted from the original DICOM format by dcm2 niigui software into 4D NIFTI format,then DKE software was used to decompose the DKI parameters into a few metrics,including mean kurtosis(MK),fractional anisotropy(FA)and mean diffusivity(MD);each parameter was processed by SPM software for image registration,segmentation,spatial standardization and smoothing,and finally the preprocessed DKI parameter map of each subject was obtained;The HC group’s gray matter was extracted after image segmentation,and the REST and xjview software were used to make the gray matter template.(4)Statistical analysis: The two-sample t test in REST software was used to obtain the brain regions with different parameters between the two groups;the results were rendered by Rest Slice viewer and Brain Net software after Gaussian random field correction(GRF);The DKI parameters of different brain regions between the two groups were extracted and Spearman correlation analysis was conducted with the disease duration、MMSE、Mo CA and UPDRS-III scores respectively.The receiver operating characteristic curve(ROC)was drawn by Med Calc statistical software to determine the diagnostic performance of each DKI parameter.Results:Compared with the healthy control group,the FA and MK value in PD group were decreased,the MD value was increased,and the differences were statistically significant(P<0.05).The brain region with decreased FA value was the left thalamus;the brain regions with decreased MK value were bilateral superior temporal gyrus,thalamus and caudate nucleus.The brain regions with increased MD value were bilateral middle temporal gyrus,superior temporal gyrus,insula,caudate nucleus,left middle frontal gyrus,superior frontal gyrus and right inferior temporal gyrus,fusiform gyrus and hippocampus.Except that the MD values of the right superior temporal gyrus(r=0.32,p=0.02),the right lobe(r=0.35,p=0.01),the left caudate nucleus(r=0.32,p=0.03)and the right caudate nucleus(r=0.36,p=0.01)were positively correlated with the UPDRS-III score,there was no significant association between DKI parameters of PD patients with the course of disease、MMSE、Mo CA and UPDRS-III scores(P>0.05).Among the diagnostic efficacy of DKI parameters for PD patients,the AUC of MK value of the left superior temporal gyrus was 0.914,indicating a high diagnostic accuracy.Except the AUC of the MD value of the left middle frontal gyrus and the left superior frontal gyrus was less than 0.7,the AUC of the DKI parameters of the other different brain regions was between 0.7 and 0.9,with medium diagnostic accuracy.Conclusion:PD patients showed abnormalities in wide-spread gray matter structure.the microstructural complexity of brain tissue decreased,especially in deep basal nuclei,bilateral temporal lobe and frontal cortex;As a non-invasive new magnetic resonance technology,DKI can detect subtle changes in the gray matter microstructure of the brain of PD patients,MK value has certain diagnostic efficacy and can be used as a potential neuroimaging marker to provide a strong basis for the diagnosis of PD.