Differential microstructural and morphological abnormalities in mild cognitive impairment and Alzheimer's disease: Evidence from cortical and deep gray matter.
One aim of this study is to use non-Gaussian diffusion kurtosis imaging (DKI) for capturing microstructural abnormalities in gray matter of Alzheimer's disease (AD). The other aim is to compare DKI metrics against thickness of cortical gray matter and volume of deep gray matter, respectively. A cohort of 18 patients with AD, 18 patients with amnestic mild cognitive impairment (MCI), and 18 normal controls underwent morphological and DKI MR imaging. Images were investigated using regions-of-interest-based analyses for deep gray matter and vertex-wise analyses for cortical gray matter. In deep gray matter, more regions showed DKI parametric abnormalities than atrophies at the early MCI stage. Mean kurtosis (MK) exhibited the largest number of significant abnormalities among all DKI metrics. At the later AD stage, diffusional abnormalities were observed in fewer regions than atrophies. In cortical gray matter, abnormalities in thickness were mainly in the medial and lateral temporal lobes, which fit the locations of known early pathological changes. Microstructural abnormalities were predominantly in the parietal and even frontal lobes, which fit the locations of known late pathological changes. In conclusion, MK can complement conventional diffusion metrics for detecting microstructural changes, especially in deep gray matter. This study also provides evidence supporting the notion that microstructural changes predate morphological changes. Hum Brain Mapp 38:2495-2508, 2017. © 2017 Wiley Periodicals, Inc.
Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California.|Brain Imaging and Analysis Center, Duke University School of Medicine, Durham, North Carolina.
Nan-Jie
0000-0001-9249-413X
NJ
Gong
Department of Geriatrics & Medicine, United Christian Hospital, Hong Kong, China.
Chun-Chung
CC
Chan
Department of Psychiatry, United Christian Hospital, Hong Kong, China.
Lam-Ming
LM
Leung
Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
Chun-Sing
CS
Wong
Center for In Vivo Microscopy, Duke University School of Medicine, Durham, North Carolina.
Russell
R
Dibb
Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California.|Helen Wills Neuroscience Institute, University of California, Berkeley, California.|Brain Imaging and Analysis Center, Duke University School of Medicine, Durham, North Carolina.|Department of Radiology, Duke University School of Medicine, Durham, North Carolina.
Chunlei
C
Liu
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000000981:diagnostic imaging / Q000473:pathology*; D001931:Brain Mapping; D060825:Cognitive Dysfunction / Q000000981:diagnostic imaging / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D066128:Gray Matter / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales
Alzheimer's disease; cortical thickness; diffusion kurtosis imaging; diffusion tensor imaging; gray matter; microstructure; mild cognitive impairment; volume