title: Arterial spin labeling measurement of cerebral perfusion in children with sickle cell disease.
abstract: OBJECTIVE
  To evaluate the applicability of arterial spin labeling (ASL) cerebral blood flow (CBF) measurements in children with sickle cell disease (SCD).
  
  
  METHODS
  We included 12 patients and five controls. Conventional magnetic resonance imaging (MRI) (T2, fluid attenuated inversion recovery [FLAIR], and MR angiography) was performed to diagnose silent infarcts, vasculopathy, or leukoencephalopathy. Pseudo-continuous ASL was performed to measure CBF using two postlabeling delays to identify transit-time effects. Perfusion estimates were corrected for hematocrit and blood velocity in the labeling plane and compared to phase-contrast MR. CBF asymmetries between the flow maps of the left and right internal carotid arteries were tested for significance using paired t-tests. Significant asymmetries were expressed in terms of an asymmetry ratio (AR = absolute difference/mean). An AR >10% was considered clinically relevant.
  
  
  RESULTS
  Mean CBF was higher in patients than in controls. Agreement between CBF and flow improved after applying hematocrit and velocity corrections. At a 2100 msec postlabeling delay one patient had a clinically relevant asymmetry. No association was observed between CBF asymmetries and silent infarcts.
  
  
  CONCLUSIONS
  Care must be taken in the interpretation of ASL-CBF measurements in SCD patients. A long postlabeling delay with blood velocity correction anticipates overestimation of CBF asymmetries.
authors.affiliation: Department of Radiology, Academic Medical Center, Amsterdam, The Netherlands. S.Gevers@amc.uva.nl
authors.forename: Sanna
authors.initials: S
authors.lastname: Gevers
authors.forename: Aart J
authors.initials: AJ
authors.lastname: Nederveen
authors.forename: Karin
authors.initials: K
authors.lastname: Fijnvandraat
authors.forename: Sandra M
authors.initials: SM
authors.lastname: van den Berg
authors.forename: Pim
authors.initials: P
authors.lastname: van Ooij
authors.forename: Dennis F
authors.initials: DF
authors.lastname: Heijtel
authors.forename: Harriët
authors.initials: H
authors.lastname: Heijboer
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Nederkoorn
authors.forename: Marc
authors.initials: M
authors.lastname: Engelen
authors.forename: Matthias J
authors.initials: MJ
authors.lastname: van Osch
authors.forename: Charles B
authors.initials: CB
authors.lastname: Majoie
mesh_terms: D000293:Adolescent; D000755:Anemia, Sickle Cell / Q000150:complications / Q000473:pathology* / Q000503:physiopathology*; D001783:Blood Flow Velocity; D002560:Cerebrovascular Circulation; D002561:Cerebrovascular Disorders / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology*; D002648:Child; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013113:Spin Labels; D055815:Young Adult
chemical_list: D013113:Spin Labels