title: Inflow-vascular space occupancy (iVASO) reproducibility in the hippocampus and cortex at different blood water nulling times.
abstract: Inflow-vascular space occupancy (iVASO) measures arterial cerebral blood volume (aCBV) using accurate blood water nulling (inversion time [TI]) when arterial blood reaches the capillary, i.e., at the arterial arrival time. This work assessed the reproducibility of iVASO measurements in the hippocampus and cortex at multiple TIs.
  
  
  
  The iVASO approach was implemented at multiple TIs in 10 healthy volunteers at 3 Tesla. aCBV values were measured at each TI in the left and right hippocampus, and the cortex. Reproducibility of aCBV measurements within scans (same day) and across sessions (different days) was assessed using the intraclass correlation coefficient (ICC).
  
  
  
  Overall hippocampal aCBV was significantly higher than cortical aCBV, likely due to higher gray matter volume. Hippocampal ICC values were high at short TIs (≤914 ms; intrascan values = 0.80-0.96, interscan values = 0.61-0.91). Cortically, high ICC values were observed at intermediate TIs of 914 (intra: 0.93, inter: 0.87) and 1034 ms (intra: 0.96, inter: 0.86). The ICC values were comparable to established contrast-based CBV measures.
  
  
  
  iVASO measurements are reproducible within and across sessions. TIs for iVASO measurements should be chosen carefully, taking into account heterogeneous arterial arrival times in different brain regions. Magn Reson Med 75:2379-2387, 2016. © 2015 Wiley Periodicals, Inc.
authors.affiliation: Vanderbilt University Institute of Imaging Science, Radiology and Radiological Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee.
authors.forename: Swati
authors.initials: S
authors.lastname: Rane
authors.affiliation: Psychiatry, Vanderbilt University School of Medicine, Nashville, Tennessee.
authors.forename: Pratik
authors.initials: P
authors.lastname: Talati
authors.affiliation: Vanderbilt University Institute of Imaging Science, Radiology and Radiological Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee.|Psychiatry, Vanderbilt University School of Medicine, Nashville, Tennessee.|Neurology, Vanderbilt University School of Medicine, Nashville, Tennessee.
authors.forename: Manus J
authors.initials: MJ
authors.lastname: Donahue
authors.affiliation: Psychiatry, Vanderbilt University School of Medicine, Nashville, Tennessee.
authors.forename: Stephan
authors.initials: S
authors.lastname: Heckers
mesh_terms: D000328:Adult; D001810:Blood Volume / Q000502:physiology; D002540:Cerebral Cortex / Q000098:blood supply* / Q000000981:diagnostic imaging*; D002560:Cerebrovascular Circulation / Q000502:physiology; D005260:Female; D006624:Hippocampus / Q000098:blood supply* / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results; D055815:Young Adult
keywords: cerebral blood flow; cerebral blood volume; cortex; hippocampus; iVASO; reproducibility