title: Changes of gray matter volume and amplitude of low-frequency oscillations in amnestic MCI: An integrative multi-modal MRI study.
abstract: BACKGROUND
  Numerous studies have reported that the amnestic-type mild cognitive impairment (aMCI) patients have impaired brain structural integrity and functional alterations separately.
  
  
  OBJECTIVE
  To investigate the changes of gray matter and amplitude of low-frequency oscillations in patients with aMCI by combining structural and functional magnetic resonance imaging (fMRI).
  
  
  METHODS
  Thirty-four patients with aMCI and 34 controls were recruited. We adopted optimized voxel-based morphometry to detect regions with gray matter volume (GMV) loss induced by aMCI. Then regional differences in amplitude of slow-4 band (0.027-0.073 Hz) oscillations among these regions between patients and healthy controls were examined. Both slow-4 amplitude of low-frequency fluctuations (ALFF) and slow-4 fractional ALFF (fALFF; the relative amplitude that resides in the low frequencies) were employed.
  
  
  RESULTS
  Patients with aMCI demonstrated significant GMV loss in the ventral medial prefrontal cortex (vMPFC), posterior cingulate cortex (PCC), bilateral hippocampus, right superior parietal gyrus, left insula and left middle temporal gyrus (P < 0.01). The patients exhibited significant decreases of slow-4 ALFF in the left hippocampus (P = 0.05) and PCC (P = 0.02), while the decreased slow-4 fALFF was detected in PCC (P = 0.01) and increased slow-4 fALFF in vMPFC (P = 0.03). In PCC, aMCI and controls exhibited significant different GMV-fALFF correlation (P < 0.05), with opposite correlation trend.
  
  
  CONCLUSIONS
  The correlates between anatomical deficits and functional alterations in aMCI suggest that anatomical and functional deficits are linked to each other. The differences of GMV-fALFF correlations demonstrated altered anatomical-functional relationship in aMCI.
authors.affiliation: Department of Radiology, Xuanwu Hospital of Capital Medical University, Beijing, PR China Beijing Key Laboratory of Magnetic Resonance Imaging and Brain Informatics, Beijing, PR China.
authors.forename: Zhi-Lian
authors.initials: ZL
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Behavioral Science, Laboratory for Functional Connectome and Development, Magnetic Resonance Imaging Research Center, Institute of Psychology, Chinese Academy of Sciences, Beijing, PR China Psychiatry Research Center, Beijing Huilongguan Hospital, Beijing, PR China.
authors.forename: Feng-Mei
authors.initials: FM
authors.lastname: Fan
authors.affiliation: Department of Radiology, Xuanwu Hospital of Capital Medical University, Beijing, PR China Beijing Key Laboratory of Magnetic Resonance Imaging and Brain Informatics, Beijing, PR China.
authors.forename: Jie
authors.initials: J
authors.lastname: Lu
authors.affiliation: Psychiatry Research Center, Beijing Huilongguan Hospital, Beijing, PR China.
authors.forename: Hui-Jie
authors.initials: HJ
authors.lastname: Li
authors.affiliation: Department of Neurology, Beijing Tongren Hospital affiliated to Capital Medical University, Beijing, PR China.
authors.forename: Long-Fei
authors.initials: LF
authors.lastname: Jia
authors.affiliation: Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Han
authors.affiliation: Department of Radiology, Xuanwu Hospital of Capital Medical University, Beijing, PR China Beijing Key Laboratory of Magnetic Resonance Imaging and Brain Informatics, Beijing, PR China kuncheng.li@gmail.com.
authors.forename: Kun-Cheng
authors.initials: KC
authors.lastname: Li
mesh_terms: D000368:Aged; D000647:Amnesia / Q000150:complications / Q000473:pathology*; D001931:Brain Mapping / Q000379:methods*; D060825:Cognitive Dysfunction / Q000150:complications / Q000473:pathology*; D005260:Female; D066128:Gray Matter / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male
keywords: VBM; aMCI; low-frequency oscillations; resting-state fMRI