title: Effects of arterial transit delay on cerebral blood flow quantification using arterial spin labeling in an elderly cohort.
abstract: To investigate whether measurement of arterial transit time (ATT) can improve the accuracy of arterial spin labeling (ASL) cerebral blood flow (CBF) quantification in an elderly cohort due to the potentially prolonged ATT in the cohort.
  
  
  
  We employed a 1-minute, low-resolution (12 mm in-plane), sequential multidelay ATT measurement (both with and without vessel suppression) approach to characterize and correct ATT errors in CBF imaging of an elderly, clinical cohort. In all, 140 nondemented subjects greater than 70 years old were imaged at 3T with a single delay, volumetric continuous ASL sequence and also with the fast ATT measurement method. Nine healthy young subjects (28 ± 6 years old) were also imaged.
  
  
  
  ATTs measured without vessel suppression (superior frontal: 1.51 ± 0.27 sec) in the elderly were significantly shorter than those with suppression (P < 0.0001). Correction of CBF for ATT significantly increased average CBF in multiple brain regions where ATT was longer than the postlabeling delay (P < 0.01) and decreased intersubject variability of CBF in frontal, parietal, and occipital regions (P < 10-8). Measured ATT with vessel suppression was significantly longer in the elderly subjects (eg, superior frontal: 1.76 ± 0.25 sec) compared to the younger adults (superior frontal: 1.59 ± 0.19 sec) in basal ganglia and frontal cortical regions (P < 0.05).
  
  
  
  The ATT measurement is beneficial for imaging of elderly clinical populations. If ATT mapping is not feasible or available, postlabeling delays of 2-2.3 seconds should be used for elderly populations based on longest measured regional ATTs.
  
  
  
  1 J. Magn. Reson. Imaging 2017;45:472-481.
authors.affiliation: Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA.|Department of Computer Science, State University of New York at Binghamton, Binghamton, New York, USA.
authors.forename: Weiying
authors.initials: W
authors.lastname: Dai
authors.affiliation: Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Tamara
authors.initials: T
authors.lastname: Fong
authors.affiliation: Department of Psychiatry and Human Behavior and Neurology, Warren Alpert Medical School, Brown University, Providence, Rhode Island, USA.
authors.forename: Richard N
authors.initials: RN
authors.lastname: Jones
authors.affiliation: Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Edward
authors.initials: E
authors.lastname: Marcantonio
authors.affiliation: Institute for Aging Research, Hebrew SeniorLife, Boston, Massachusetts, USA.
authors.forename: Eva
authors.initials: E
authors.lastname: Schmitt
authors.affiliation: Institute for Aging Research, Hebrew SeniorLife, Boston, Massachusetts, USA.|Department of Gerontology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Sharon K
authors.initials: SK
authors.lastname: Inouye
authors.affiliation: Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: David C
authors.initials: DC
authors.lastname: Alsop
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity / Q000502:physiology*; D002533:Cerebral Angiography / Q000379:methods*; D002536:Cerebral Arteries / Q000000981:diagnostic imaging* / Q000502:physiology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013113:Spin Labels
chemical_list: D013113:Spin Labels
keywords: arterial spin labeling; arterial transit time; cerebral blood flow; elderly cohort; magnetic resonance imaging