VBM And MR-DKI Primary Study Of Brain Structural Changes In Sle Patients Without Obvious Neuropsychiatric Symptoms

Objective: In this study,we used voxel based morphometry(VBM)and diffusion kurtosis imaging(DKI)to measure brain structural changes of systemic lupus erythematosus(SLE)patients without obvious neuropsychiatric symptoms,and to investigate the value of VBM and DKI in evaluating microstructure changes of SLE patients without obvious neuropsychiatric symptoms.Material and method: Our study included 41 SLE patients without obvious neuropsychiatric symptoms and 37 healthy controls with age,sex and education level matched.All patient were given Montreal cognitive assessment(MoCA)test,Hamilton Depression Scale(HAMD)test,Digit Symbol Test(DST)and Systemic Lupus Erythematosus Disease Activity Index(SLEDAI)test.All subjects performed regular head MRI sequence,T1-weighted volumetric images and DKI scans.The post-processing and statistical analysis of the three-dimensional brain volume images are accomplished by using SPM8 software package,the images of DKI were transmitted to image post-processing work station to deal with the images and measure the data.Record the value of(mean kurtosis)MK,(Mean diffusivity)MD,(axial kurtosis)AK,(radial kurtosis)RK in bilateral frontal-WM,bilateral posterior cingulate gyrus(PCG),bilateral dorsal thalamus,bilateral lentiform nucleus,bilateral caput nuclei caudati,genu and splenium of corpus callosum.Measured DKI data were statistically analyzed.Results: 1.Compared to healthy controls,SLE patients had significantly decreased grey matter volume in temporal lobe,parietal lobe,rontal_Inf_Orb_R(aal),Frontal_Sup_R(aal),inferior frontal gyrus,frontal lobe,Frontal_Inf_Oper_R(aal).2.Compared to healthy controls,the MK value in SLE group significantly decreased in bilateral frontal-WM,bilateral PCG,bilateral dorsal thalamus(P<0.05),the MD value in SLE group significantly increased in right dorsal thalamus,bilateral dorsal thalamus(P<0.05),the AK value in SLE group significantly decreased in bilateral frontal-WM,right PCG,right dorsal thalamus(P<0.05),the RK value in SLE group significantly decreased in right frontal-WM,bilateral PCG,bilateral dorsal thalamus,splenium of corpus callosum(P<0.05).3.Negative correlation among SLEDAI score and the value of MK,AK,RK were detected in SLE group(r values are-0.414,-0.323,-0.421 respectively,P is less than 0.05),there is a positive correlation between the MD value of the right PCG and the SLEDAI score(r=-0.391,P<0.05).Negative correlation among the MD value of the right frontal-WM and DST score(r=-0.352,P<0.05)were detected in SLE group,there is a positive correlation between the MD value of the left PCG and the DST score(r values are-0.414,-0.323,-0.421 respectively,P is less than 0.05),the MD value of the left thalamus was negatively correlated with the DST score(r=-0.364,P<0.05),and the AK value of the right thalamus was positively correlated with the DST score(r=0.422,P<0.05).Conclusion: VBM results show SLE patients without obvious neuropsychiatric symptoms had decreased grey matter volume in some part of the brain,and the changes in the microstructure of the patient’s head can be detected by the DKI parameters,which provide reference for the pathogenesis of neuropsychiatric systemic lupus erythematosus(NPSLE).In SLE group,some of the DKI parameters in some part of the brain are associated with some clinical data,which may be an independent parameter to evaluate patient’s condition.