title: Different post label delay cerebral blood flow measurements in patients with Alzheimer's disease using 3D arterial spin labeling.
abstract: OBJECTIVE
  To evaluate cerebral blood flow (CBF) in patients with Alzheimer's disease (AD) using a three-dimensional pseudocontinuous arterial spin labeling (PCASL). We aimed to study the effects of different post label delay on the resulting CBF maps and to investigate the characteristics and clinical applications of brain perfusion.
  
  
  METHODS
  Sixteen AD patients and nineteen healthy control subjects were recruited. 3D PCASL was performed using a 3.0 T MR scanner. ASL was performed twice with different post label delays (PLD). Comparisons of CBF were made between AD patients and healthy control subjects respectively with PLD of 1.5 s and PLD of 2.5 s. Relationship between the CBF values and cognition was investigated using correlation analysis. A receiver operating characteristic (ROC) curve was generated for CBF measurements in posterior cingulate region.
  
  
  RESULTS
  AD patients with PLD of 1.5 s showed lower CBF values primarily in bilateral temporal lobes, precuneus, middle and posterior cingulate gyri, left inferior parietal gyrus, left angular gyrus and left superior frontal gyrus. Lowered cerebral values were also observed in similar regions with PLD of 2.5 s, but the clusters of voxel were smaller. CBF values were associated with cognition scores in most of gyri mentioned above.
  
  
  CONCLUSIONS
  Hypoperfusion areas were observed in AD patients. PLD of 1.5s was sufficient to display CBF. Considering the complicated AD pathology, multiple PLDs are strongly recommended.
authors.affiliation: Department of Radiology, Peking University Third Hospital, Beijing, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Radiology, Peking University Third Hospital, Beijing, China.
authors.forename: Xiangzhu
authors.initials: X
authors.lastname: Zeng
authors.affiliation: Department of Radiology, Peking University Third Hospital, Beijing, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Neurology, Peking University Third Hospital, Beijing, China.
authors.forename: Na
authors.initials: N
authors.lastname: Zhang
authors.affiliation: Department of Neurology, Peking University Third Hospital, Beijing, China.
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Fan
authors.affiliation: Department of Radiology, Peking University Third Hospital, Beijing, China. Electronic address: huishuy@sina.com.
authors.forename: Huishu
authors.initials: H
authors.lastname: Yuan
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000503:physiopathology*; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping / Q000379:methods; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008297:Male; D012372:ROC Curve; D013113:Spin Labels
chemical_list: D013113:Spin Labels
keywords: Alzheimer's disease; Arterial spin labeling (ASL); Cerebral blood flow; Post label delay