Diffusion tensor imaging of white matter lesions with cognitive impairment

Abstract

Objective To explore abnormal microstructural changes of white matter in patients with white matter lesions using diffusion tensor imaging(DTI), and to determine the association of such abnormalities of DTI parameters with cognitive function. Methods The objects who have already confirmed with WML were collected from March 2012 to February 2018 through magnetic resonance imaging (MRI) scan from the neurology department of Beijing Tiantan Hospital.Use The hamilton depression scale(HAMD) and the hamilton anxiety scale(HAMA) to eliminate anxiety and depression, and divided into WML-CN group, WML-VCIND group and WML-VAD group with Mini-mental state examination (MMSE), Montreal Cognitive Assessment (MOCA)and clinical dementia rating(CDR). In addition, select the healthy elderly people without WML by MRI scan as the normal control group.All of the subjects were detected with the superconduct magnetic resonance imaging system (German SIEMENS 3.0T ) for the DTI scanning.Original images were processed with VBA.Then explore the changes of FA and MD of DTI in whole brain and regions of interest in NC group, WML-CN group, WML-VCIND group and WWML-VAD group, and its correlation with the severity of cognitive impairment in patients with WML. Results The damage degree of the fiber microstructure of brain white matter was significantly correlated with the total grade point of MoCA (P<0.01). In figure FA, the variance analysis of F test results showed that the significant brain areas were the splenium of the corpus callosum, the genu of corpus callosum, bilateral posterior internal capsule, retrolenticular part of internal capsule, anterior thalamic radiation, partial inferior longitudinal fasciculus and inferior fronto-occipital fasciculus, cingulate, external capsule, upper and posterior part of the radiation crowns, partial superior longitudinal fasciculus, etc.(P<0.05 after FWE correction based on TFCE method). In Figure MD, the variance analysis of F test results showed that the statistically significant brain areas mainly included the left external capsule and hook, partial genu and splenium of corpus callosum, Bilateral, bilateral inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, anterior thalamic radiation, retrolenticular part of internal capsule, cingulate, etc (P<0.05 after FWE correction based on TFCE). Conclusion No matter whether cognitive impairment exists in patient with WML or not, all DTI parameters are different from those of normal people.The integrity of white matter fiber has been damaged with different degrees.The more severe the cognitive impairment in the external manifestations of patients with WML, the greater the damage to the intrinsic white matter microstructure. Key words: White matter lesions; Cognitive impairment; Diffusion tensor imaging; White matter fiber