Diffusion Kurtosis Imaging Study Of Brain Microstructure In Neuromyelitis Optica

Objective:This study used diffusion kurtosis imaging(DKI)technology to detect the brain of neuromyelitis optica(NMO)patients and healthy control groups,aiming to compare and analyse the changes of neuromyelitis patients with intracranial microstructure,as well as investigate the value of DKI for diagnosis and prognosis evaluation of NMO.Materials and methods:We collected ten NMO patients admitted to the Department of Neurology at the first affiliated hospital of Dalian Medical University from November 2014 to December 2016 as the case group.All the patients conform to the standard of Wingerchuk NMO diagnosis in 2006.Our study included one male patient and nine female patients,who aged from 28 to 53 years,with an average age of(41.1±8.49).They were all evaluated by Expanded Disability Status Scale(EDSS).At the same time,we also choose 10 healthy volunteers matched for age and sex as control groups.In the case of all participants consenting to our study,we use a 3.0T MRI to get the pictures of routine and DKI sequence.Then we input the obtained original images into the ADW 4.4 processing station.We use the Functool software to analyze the images.Finally we can get the corresponding image of RK?AK?MK?RD?AD?MD.Then we can get the value of parameters(RK?AK?MK?RD?AD?MD)in the region of interest among white matte(WM),such as parietal lobe-WM,occipital lobe-WM,temporal lobe-WM,frontal lobe-WM.and the fiber tracts such as anterior limb of internal capsule(ALIC),posterior limb of internal capsule(PLIC),splenium of corpus callosum(SCC)and knee of corpus callosum(KCC).Because gray matter has a highly isotropic,we only measured MD and MK values in caudate nucleus,thalamus,globus pallidus and putamen.Each part of the region of interest at the same level should be measured for 3 times,regarding the average value as the final result.SPSS 21 statistical software was used to analyze the DKI parameters.The DKI parameters obtained on two groups of detected area were comparing by two independent samples t-test to find if there are any differences between the two groups.Spearmans correlation analysis is used to clear the correlation between DKI parameters and EDSS scales.The P-value less than 0.05 is regarded as the standard with statistical difference.Results:1.The AK and MK values of white matter and fiber tracts in the NMO groups were higher than those in the HC groups,but only the AK value of the temporal lobe-WM was significantly higher(P<0.05).The RK value of frontal lobe-WM,parietal lobe-WM,occipital lobe-WM,ALIC,PLIC,SCC and KCC in the NMO groups increased slightly,but the RK value of temporal lobe-WM decreased slightly.2.The RD value of temporal lobe-WM.occipital lobe-WM and PLIC in the NMO groups significantly decreased(P<0.05).The MD value of parietal lobe-WM,occipital lobe-WM,temporal lobe-WM,frontal lobe-WM,ALIC,PLIC and SCC in the NMO groups were lower.And the AD value of parietal lobe-WM,temporal lobe-WM,frontal lobe-WM,ALIC,PLIC,SCC and KCC in the NMO groups decreased(P<0.05).3.The MK value of globus increased significantly in NMO groups than HC groups.And the MD value of all gray nucleus decreased significantly(P<0.05).4.The MK value of putamen,frontal lobe,and the AK value of parietal lobe and SCC was negatively correlated with the EDSS score(P<0.05).Conclusion:1.DKI is a new MRI technology that quantifies the diffusion of non aqueous Gauss molecules in human body.It can be more realistic and sharp enough to detect subtle changes in tissue structure.2.Compared with conventional MRI,DKI can be used to detect the early NMO damage,which is helpful to the early diagnosis of the disease.3.The MK and AK values of DKI can assess the prognosis of patients with NMO.