Application Study Of Diffusion Kurtosis Imaging In The Brain Of Patients With Diabetic Retinopathy

Objective: Using diffusion kurtosis imaging(DKI)to explore the characteristics of the microstructural changes of whole brain regions in patients with type 2 diabetic retinopathy(DR)with negative conventional magnetic resonance imaging and analyze the correlation between it and cognitive function.Methods: Twenty-six patients with DR in Affiliated Hospital of Zunyi Medical University from October 2019 to October 2020 were selected as case group,aged from 40 to 60 years old.In the same period,27 healthy volunteers who matched their age,sex and education level with the case group were recruited as the control group.The cognitive function of the case group and the control group were evaluated,the evaluation results were recorded,and the clinical information of all subjects was collected for follow-up analysis.All subjects were scanned by MRI(3D-T1 WI structure image,diffusion tensor imaging,T2-FLAIR)and DKI sequence with 3.0T MRI scanner.MRIcorn was used software to convert dicom image format to nii file format,and FMRIB software library(FSL)was used software for eddy current correction.After batch processing with diffusion kurtosis estimator(DKE)software,the parameter diagrams of DKI were obtained.Statistical Parametric Mapping(SPM)based on MATLAB software was used to register all DKI parameter images to the standard space and smooth it.Then the parameters of the two groups were compared and analyzed,and the brain areas with statistically differences were extracted.The coordinates and voxel values of the different brain regions were recorded.Extracting the average values of whole brain tensor and kurtosis parameters in patients with type2 diabetic retinopathy by masbar software and analyzed by Pearson correlation analysis with clinical variables(course of disease,blood glucose and cognitive state).Results: The scores of cognitive assessment in the case group were lower than those in the normal control group(p<0.001).There was no statistical difference in sex,age and education level between the two groups(all p>0.05).Compared with the control group,the case group showed that the axial kurtosis(AK),mean kurtosis(MK),and radial kurtosis(RK)values of bilateral superior temporal gyrus,frontotemporal white matter,marginal lobe,parahippocampal gyrus,lingual gyrus,corpus callosum,caudate nucleus and precuneus decreased.The fractional anisotropy(FA)values of bilateral thalamus,corpus callosum and bilateral caudate nucleus decreased.The axial diffusivity(AD),radial diffusivity(RD)and mean diffusivity(MD)values of bilateral middle occipital gyrus,cerebellum,frontotemporal gray matter,marginal lobe,hippocampus,parahippocampal gyrus,cingulate gyrus,lingual gyrus,corpus callosum,anterior cuneus,taloid gyrus,left transverse temporal gyrus and superior temporal gyrus increased.Pearson correlation analysis showed that the average RD values of right anterior cingulate gyrus were negatively correlated with Mini-mental State Examination(MMSE)score(r=-0.153,p=0.048).Conclusion: The study based on DKI showed that the microstructural changes of multiple brain regions in patients with conventional MRI-negative DR.The RD values of right anterior cingulate gyrus were negatively correlated with MMSE score,which provide new evidence for the pathophysiological mechanism of diabetic encephalopathy.