Study Of Multimodel Magnetic Resonance Imaging On Anti-N-methyl-D-aspartate Receptor Encephalitis

PART ONE STUDY OF LESIONS OF ANTI-N-METHYL-D-ASPARTATE RECEPTOR ENCEPHALITIS BY DIFFUSION WEIGHTED IMAGINGObjective: To investigate characteristic of the diffusion weighted imaging(DWI)in patients with anti-N-methyl-D-aspartate(NMDA)receptor encephalitis.Material and Methods:(1)Retrospective analysis were performed on 66 defined patients with anti-NMDA receptor encephalitis in our hospital.All the patients underwent conventional head magnetic resonance imaging(MRI)and DWI scans.(2)The signal,distribution,and enhancement of the lesions on the conventional MRI and the appearance of the lesions on the DWI and the apparent diffusion coefficient(ADC)images were observed.According to the signal characteristics of the lesions on T1-weighted iamging(T1WI)and ADC image,the lesions were divided into isointense lesions and hypointense lesions on T1 WI,hypointense lesions and hyperintense lesions on ADC images.(3)The ADC values of the lesions and the contralateral normal brain tissues were measured.Comparison of differences of ADC values were performed between the all lesions and the contralateral normal brain tissues,between the isointenselesions and the hypointense lesions on T1 WI,and between the hypointense lesions and the hyperintense lesions on the ADC images.(4)Correlations of the ADC values of the lesions with the disease duration and the modified ranking scale(m RS)scores were analyzed.Results:(1)A total of 29 lesions were found in 22 out of 66 patients(33.33%)on the conventional MRI.Most of the lesions were mainly located in the cerebral cortex,and a few of lesions were located in the bilateral hippocampi,the bilateral thalamus,the bilateral basal ganglia regions,the bilateral periaqueductal gray,the cingulate gyrus,the corpus callosum,and the cerebellum,et al..Interestingly,symmetrical abnormal signal of the bilateral cortical spinal tracts(CSTs)were observeed in two patients.(2)Of the 29 lesions,20 were isointense and 9 were hypointense on T1 WI,respectively.(3)Lesions in 27 cases were slightly hyperintense or significant hyperintense on T2-weihted imaging(T2WI)and fluid-attenuated inversion recovery(FLAIR)sequence and slightly hypertense or significant hypertense on corresponding DWI.However,lesions in 2 cases were subcortical gyrus-like hypointense on FLAIR.(3)Most of the lesions showed isointense,slightly hyperintense and significant hyperintense on DWI.(4)Seven isointense lesions on T1 WI were hypointense on the ADC images,while the other twenty-two lesions(13isointense lesions and 9 hypointense lesions on T1WI)were slightly hyperintense or significant hyperintense on the ADC images.(5)Comparison of ADC values between the hypointense and hyperintense lesions on ADC images and the contalateral normal brain tissues,respectively.The ADC values of the seven hypointense lesions((0.69 ±0.01)× 10-3 mm2 / s)on ADC images were lower than that of the contralateral normal brain tissues((0.76 ± 0.02)× 10-3 mm2 / s)(t = 9.62,P< 0.001),while the ADC values of the 22 hyperintense lesions((0.86 ± 0.10)× 10-3 mm2 / s)on ADC images were higher than that of the contralateral normal brain tissues((0.74 ± 0.05)× 10-3 mm2 / s))(t = 16.999,P < 0.001).(6)Comparison of ADC values between different signal lesions on T1 WI.ADC values of the 20 isointense lesions((0.82 ± 0.10)× 10-3 mm2 / s)were lower than that of 9 hypointense lesions((0.95 ± 0.16)× 10-3 mm2 / s)on T1WI(t =-5.48,P < 0.001).(7)There was a positive correlation between the lesion ADC values and the disease duration of the patients(r = 0.61,P< 0.005),but no correlation was found between the ADC values of the lesions and the m RS scores of the patients(r = 0.09,P = 0.68).Conclusion: The quantitative index ADC value of DWI can help to identify the pathological changes of anti-NMDA receptor encephalitis in different periods and different signals,contributing to the diagnosis of this disease.PART TWO 3D PSEDO-CONTINOUS ARTERIAL SPIN LABELING PERFUSION IMAGING EVALUATES PERFUSION CHANGES IN ANTI-NMDA RECEPTOR ENCEPHALITIS AND ITS CORRELATION WITH CLINICAL SCORESObjective: To investigate cerebral perfusion changes in patients with anti-N-methyl-D-aspartate(NMDA)receptor encephalitis by using three-dimensional pseudo-continuous arterial spin labeling(3D pCASL)perfusion imaging technique and its correlation with modified rankin scale(m RS)score and other clinical cognition scale scores.Material and Methods:(1)A totoal of 48 patients with stable anti-NMDA receptor encephalitis and 40 cases of age,gender and education matched healthy controls(HCs)were recruited in our study.The m RS and varied clinical cognition scale scores were performed in these two groups before magnetic resonance imaging(MRI)scanning.(2)All subjects underwent whole-brain conventional T2-weighted imaging(T2WI),T2-fluid attenuated inversion recovery(FLAR),3D T1-weighted imaging(T1WI)and 3D pCASL scans.After the plain scans,gadolinium was injected to acquired enhancement images.(2)The SPM8 software was used to preprocess the images.Cerebral perfusion differences between patients and HCs were analyzed using sex,gender,education level as covariates.(3)The values of cerebral blood flow(CBF)in significantly different brain regions were further extracted by using the REST software,analysing its correlation with m RS score and other clinical cognition scale scores.Results:(1)Compared with the HCs,the CBF values of the left medial and collateral cingulate gyrus,the left supplementary motor area(SMA),the left superior frontal gyrus,the right middle frontal gyrus,the right pars triangularis,the right pars opercularis,and the right central sulcus decreased in patients with anti-NMDA receptor encephalitis(P < 0.001).(2)The right middle frontal gyrus,the right pars triangularis,the right pars opercularis also showed medium negative correlations with the m RS scores(r =-0.516,-0.49,-0.468,respectively;P = 0.024,0.033,0.044,respectively).The right middle frontal gyrus,the right pars triangularis,the right pars opercularis,and the left medial and collateral cingulate gyrus in patients had medium positive correlations with MMSE scores(r = 0.465,0.492,0.568,0.452,respectively;P = 0.02,0.02,0.006,0.035,respectively).There were no correlations between the brain regions with significantly decreased CBF and other clinical cognition scales scores(P >0.05).Conclusion: The 3D pCASL techniche can show the cerebral hypoperfusion regions in stable patients with anti-NMDA receptor encephalitis and can evaluate its correlations with clinical scales scores,which had a good application prospect in anti-NMDA receptor encephalitis.PART THREE EVALUATION OF INTERGRITY OF WHITE MATTER FIBERS IN PATIENTS WITH ANTI-NMDA RECEPTOR ENCEPHALITIES BASED ON AUTOMATED FIBER QUANTIFICATIONObjective: To show the changes in integrity of white matters in patients with anti-NMDA receptors encephalitis based on automated fiber quantification(AFQ).Material and Methods: A total of 48 patients with anti-NMDA receptor encephalitis diagnosed in our hospital and 40 matching gender,age and education level healthy controls were recruited in this study.All subjects underwent conventional head MRI,diffusion tensor imaging(DTI)scanning,m RS and mini-mental state examination(MMSE)scores.Fractional anisotropy(FA)and mean diffusivity(MD)quantitative analyses were conducted on 100 nodes of 20 white matter fibers in all subjects' brains using AFQ to compare whether there were statistical differences,and to analysis correlations between these two parameters and m RS and MMSE scores,respectively.Result:(1)Conventional MRI showed that lesions in bilateral corticospinal tracts(CST)and hippocampi in one patients and in left frontal cortex in another patients.(2)Diffuse increase of FA values and reduction of MD values were measured on the bilateral CST,cingulum cingulate,cingulum hippocampus,and arcuat,showing significantly statistical differences from the healthy controls(P < 0.01).Diffusion indexes of the other fibers showed segmental changes,and there was no statistical difference between the two groups(P > 0.05).(3)FA values of the bilateralCST,cingulum cingulate,cingulum hippocampus,and arcuat were negatively correlated with m RS score(r =-0.81,-0.77,-0.86,-0.85,respectively;P < 0.01),and positively correlated with MMSE score(r =0.90,0.83,0.92,0.89,respectively;P < 0.01).MD values of the bilateral CST,cingulum cingulate,cingulum hippocampus,and arcuatand were positively correlated with m RS score(r = 0.84,0.77,0.88,0.77,respectively;P < 0.01),and negatively correlated with MMSE score(r =-0.92,-0.86,-0.92,-0.89,respectively;P < 0.01).Conclusion: In patients with anti-NMDA receptor encephalitis,extensive microstructural damage is found in the fiberes dominated by CST,cingulum cingulate,cingulum hippocampus,and arcuat,which is closely related to the m RS scores and MMSE scores of patients and is helpful for the diagnosis of occult lesions and explanation of the clinical symptoms.