title: Longitudinal reproducibility and accuracy of pseudo-continuous arterial spin-labeled perfusion MR imaging in typically developing children.
abstract: OBJECTIVE
  To evaluate the longitudinal repeatability and accuracy of cerebral blood flow (CBF) measurements by using pseudo-continuous arterial spin-labeled (pCASL) perfusion magnetic resonance (MR) imaging in typically developing children.
  
  
  METHODS
  Institutional review board approval with HIPAA compliance and informed consent were obtained. Twenty-two children aged 7-17 years underwent repeated pCASL examinations 2-4 weeks apart with a 3-T MR imager, along with in vivo blood T1 and arterial transit time measurements. Phase-contrast (PC) MR imaging was performed as the reference standard for global blood flow volume. Intraclass correlation coefficient (ICC) and within-subject coefficient of variation (wsCV) were used to evaluate accuracy and repeatability.
  
  
  RESULTS
  The accuracy of pCASL against the reference standard of PC MR imaging increased on incorporating subjectwise in vivo blood T1 measurement (ICC: 0.32 vs 0.58). The ICC further increased to 0.65 by using a population-based model of blood T1. Additionally, CBF measurements with use of pCASL demonstrated a moderate to good level of longitudinal repeatability in whole brain (ICC = 0.61, wsCV = 15%), in gray matter (ICC = 0.65, wsCV = 14%), and across 16 brain regions (mean ICC = 0.55, wsCV = 17%). The mean arterial transit time was 1538 msec ± 123 (standard deviation) in the pediatric cohort studied, which showed an increasing trend with age (P = .043).
  
  
  CONCLUSIONS
  Incorporating developmental changes in blood T1 is important for improving the accuracy of pCASL CBF measurements in children and adolescents; the noninvasive nature, accuracy, and longitudinal repeatability should facilitate the use of pCASL perfusion MR imaging in neurodevelopmental studies.
authors.affiliation: Department of Radiology and Biostatistics, University of Pennsylvania Medical Center, Philadelphia, PA, USA.
authors.forename: Varsha
authors.initials: V
authors.lastname: Jain
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Duda
authors.forename: Brian
authors.initials: B
authors.lastname: Avants
authors.forename: Mariel
authors.initials: M
authors.lastname: Giannetta
authors.forename: Sharon X
authors.initials: SX
authors.lastname: Xie
authors.forename: Timothy
authors.initials: T
authors.lastname: Roberts
authors.forename: John A
authors.initials: JA
authors.lastname: Detre
authors.forename: Hallam
authors.initials: H
authors.lastname: Hurt
authors.forename: Felix W
authors.initials: FW
authors.lastname: Wehrli
authors.forename: Danny J J
authors.initials: DJ
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D016477:Artifacts; D001810:Blood Volume; D001921:Brain / Q000254:growth & development*; D001931:Brain Mapping / Q000379:methods*; D002560:Cerebrovascular Circulation; D002648:Child; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D011446:Prospective Studies; D012016:Reference Values; D015203:Reproducibility of Results; D013113:Spin Labels
chemical_list: D013113:Spin Labels