title: Non-Gaussian diffusion alterations on diffusion kurtosis imaging in patients with early Alzheimer's disease.
abstract: OBJECTIVE
  To evaluate non-Gaussian diffusion changes of the whole-brain and its correlation with cognitive performance in patients with early Alzheimer's disease (AD), using diffusion kurtosis imaging (DKI).
  
  
  METHODS
  Twenty-six patients with early AD and twenty-six normal controls underwent diffusion imaging. Seven parametric maps were calculated from multiple b-value diffusion data, including mean kurtosis (MK), axial kurtosis (AK), radial kurtosis (RK), fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AxD) and radial diffusivity (RD). Voxel-based analyses were performed to evaluate the group difference between the AD patients and normal controls. Then correlation between the diffusion parameters (MK, FA and MD) and cognitive performance were analyzed in AD patients.
  
  
  RESULTS
  For AD patients, increased MD, AxD and RD were found in white matter (WM), including the genu of corpus callosum, bilateral cingulate bundle, bilateral temporal and frontal WM, and were also found in gray matter (GM), including the bilateral temporal GM, parahippocampal gyrus, hippocampus, cingulate gyrus, thalamus, and amygdala. These regions were partially overlapped with those showing decreased FA, MK, AK and RK. However, only kurtosis indices could detect the significant differences in the lentiform nucleus between AD patients and health control. DKI indices in AD patients significantly correlated with the clinical scores in genu of CC, cingulate bundle, temporal and frontal lobe, while the voxel number showing significant correlation with MK was more than that with FA and MD.
  
  
  CONCLUSIONS
  Early AD patients already have microstructural changes in both WM and GM. DKI can provide supplementary information in reflecting these changes and may be sensitive in diagnosing early AD.
authors.affiliation: Department of Radiology, Tianjin First Central Hospital, Tianjin 300192, China.
authors.forename: Lixiang
authors.initials: L
authors.lastname: Yuan
authors.affiliation: Department of Radiology, Tianjin First Central Hospital, Tianjin 300192, China; First Central Clinical institution, Tianjin Medical University, Tianjin 300192, China.
authors.forename: Man
authors.initials: M
authors.lastname: Sun
authors.affiliation: Department of Biomedical Engineering, Tianjin University, Tianjin 300072, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Radiology, Tianjin First Central Hospital, Tianjin 300192, China.
authors.forename: Miaomiao
authors.initials: M
authors.lastname: Long
authors.affiliation: Department of Biomedical Engineering, Tianjin University, Tianjin 300072, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Department of Radiology, Tianjin First Central Hospital, Tianjin 300192, China.
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Yin
authors.affiliation: MR Collaboration NE Asia, Siemens Healthcare, Shanghai 201318, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Yan
authors.affiliation: Department of Radiology, Tianjin First Central Hospital, Tianjin 300192, China.
authors.forename: Dongxu
authors.initials: D
authors.lastname: Ji
authors.affiliation: Department of Radiology, Tianjin First Central Hospital, Tianjin 300192, China. Electronic address: nihyan@sina.com.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Ni
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000473:pathology*; D001921:Brain / Q000473:pathology*; D016022:Case-Control Studies; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D008297:Male
keywords: Alzheimer's disease; Diffusion kurtosis imaging; Non-Gaussian; Voxel-based analysis