title: Arterial Spin-Labeling Parameters Influence Signal Variability and Estimated Regional Relative Cerebral Blood Flow in Normal Aging and Mild Cognitive Impairment: FAIR versus PICORE Techniques.
abstract: OBJECTIVE
  Arterial spin-labeling is a noninvasive method to map cerebral blood flow, which might be useful for early diagnosis of neurodegenerative diseases. We directly compared 2 arterial spin-labeling techniques in healthy elderly controls and individuals with mild cognitive impairment.
  
  
  METHODS
  This prospective study was approved by the local ethics committee and included 198 consecutive healthy controls (mean age, 73.65 ± 4.02 years) and 43 subjects with mild cognitive impairment (mean age, 73.38 ± 5.85 years). Two pulsed arterial spin-labeling sequences were performed at 3T: proximal inversion with a control for off-resonance effects (PICORE) and flow-sensitive alternating inversion recovery technique (FAIR). Relative cerebral blood flow maps were calculated by using commercial software and standard parameters. Data analysis included spatial normalization of gray matter-corrected relative CBF maps, whole-brain average, and voxelwise comparison of both arterial spin-labeling sequences.
  
  
  RESULTS
  Overall, FAIR yielded higher relative CBF values compared with PICORE (controls, 32.7 ± 7.1 versus 30.0 ± 13.1 mL/min/100 g, P = .05; mild cognitive impairment, 29.8 ± 5.4 versus 26.2 ± 8.6 mL/min/100 g, P < .05; all, 32.2 ± 6.8 versus 29.3 ± 12.3 mL/min/100 g, P < .05). FAIR had lower variability (controls, 36.2% versus 68.8%, P < .00001; mild cognitive impairment, 18.9% versus 22.9%, P < .0001; all, 34.4% versus 64.9% P < .00001). The detailed voxelwise analysis revealed a higher signal for FAIR, notably in both convexities, while PICORE had higher signal predominantly in deep cerebral regions.
  
  
  CONCLUSIONS
  Overall, FAIR had higher estimated relative CBF and lower interindividual variability than PICORE. In more detail, there were regional differences between both arterial spin-labeling sequences. In summary, these results highlight the need to calibrate arterial spin-labeling sequences.
authors.affiliation: From the Divisions of Diagnostic and Interventional Neuroradiology (K.-O.L., M.-L.M., M.V., S.H.).
authors.forename: K-O
authors.initials: KO
authors.lastname: Lövblad
authors.affiliation: From the Divisions of Diagnostic and Interventional Neuroradiology (K.-O.L., M.-L.M., M.V., S.H.).
authors.forename: M-L
authors.initials: ML
authors.lastname: Montandon
authors.affiliation: From the Divisions of Diagnostic and Interventional Neuroradiology (K.-O.L., M.-L.M., M.V., S.H.) CREATIS (M.V.), UMR CNRS 5220-Institut National de la Santé et de la Recherche Médicale U1044, INSA de Lyon, Université de Lyon, Centre Hospitalier Universitaire de Saint Etienne, Saint Etienne, France.
authors.forename: M
authors.initials: M
authors.lastname: Viallon
authors.affiliation: Psychiatry (C.R., S.T., P.G.), Geneva University Hospitals, Geneva, Switzerland.
authors.forename: C
authors.initials: C
authors.lastname: Rodriguez
authors.affiliation: Psychiatry (C.R., S.T., P.G.), Geneva University Hospitals, Geneva, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Toma
authors.affiliation: Institute of Neurology (X.G.), University College London, London, United Kingdom.
authors.forename: X
authors.initials: X
authors.lastname: Golay
authors.affiliation: Psychiatry (C.R., S.T., P.G.), Geneva University Hospitals, Geneva, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Giannakopoulos
authors.affiliation: From the Divisions of Diagnostic and Interventional Neuroradiology (K.-O.L., M.-L.M., M.V., S.H.) sven.haller@hcuge.ch.
authors.forename: S
authors.initials: S
authors.lastname: Haller
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001921:Brain / Q000098:blood supply* / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D060825:Cognitive Dysfunction / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013113:Spin Labels
chemical_list: D013113:Spin Labels