The diagnostic value of MRI diffusion kurtosis imaging and diffusion tensor imaging in early Wallerian degeneration of corticospinal tract in cerebral small-vessel disease
1Department of Radiology, 4Department of Ultrasound, Shenzhen Hospital of Integrated Traditional Chinese and Western Medicine, Shenzhen 518104, China; 2Department of Radiology, Jieyang People′s Hospital, Jieyang 522000, China; 3Department of Radiology, 5Department of Neurology, the Second Affiliated Hospital of Shantou University Medical College, Shantou 515000, China
Abstract：ObjectiveBy analyzing MRI diffusional kurtosis imaging (DKI) and diffusion tensor imaging (DTI) of corticospinal tract (CST) in cerebral small-vessel disease (CSVD), the study compared their diagnostic value to detect the microstructures of early Wallerian degeneration（WD）. MethodsFrom September 2016 to April 2018, 56 patients diagnosed as CSVD in the Department of Neurology in the Second Affiliated Hospital of Shantou University Medical College, and indicated as lacunar infarction on MRI were selected as CSVD group, and 24 patients without positive findings on MRI were selected as the control group, all of them underwent DKI scan. According to the different lesion sites in MRI T2-Flair, CSVD group was divided into 4 groups, including pons group (A1 group), forepart of posterior limb of internal capsule group (A2 group), corona radiata group (A3 group) and subcortex group (A4 group). The mean kurtosis (MK),mean diffusion(MD) and fractional anisotropic of tensor (FA) were measured on the seemingly normal white matter areas on both sides of the descending fiber bundle in pons, forepart of posterior limb of internal capsule, corona radiata and subcortical area. ResultsMK values of pons in the A1，A2，A3 and A4 group (1.19±0.11, 1.18±0.11, 1.20±0.10 and 1.20±0.09, respectively) were higher than those in the control group (1.05±0.12), which showed significant differences (t=-3.47, -4.10, -5.29, -5.40, all P＜0.01). MK values of subcortex in the A1, A3 and A4 group (1.00±0.08, 1.00±0.13 and 0.99±0.13, respectively) were higher than those in the control group (0.92±0.12), which showed significant differences (t=-2.12, -2.22, -2.11，all P＜0.05). In four subgroups, the number of brain regions with statistical significance (P＜0.05) in MK, MD and FA, they were 7, 1 and 2, respectively. ConclusionDKI is more sensitive than DTI in detecting the microstructure of early WD when there is no positive result in conventional MRI.
