title: Absolute quantification of perfusion by dynamic susceptibility contrast MRI using Bookend and VASO steady-state CBV calibration: a comparison with pseudo-continuous ASL.
abstract: OBJECTIVE
  Dynamic susceptibility contrast MRI (DSC-MRI) tends to return elevated estimates of cerebral blood flow (CBF) and cerebral blood volume (CBV). In this study, subject-specific calibration factors (CFs), based on steady-state CBV measurements, were applied to rescale the absolute level of DSC-MRI CBF.
  
  
  METHODS
  Twenty healthy volunteers were scanned in a test-retest approach. Independent CBV measurements for calibration were accomplished using a T1-based contrast agent steady-state method (referred to as Bookend), as well as a blood-nulling vascular space occupancy (VASO) approach. Calibrated DSC-MRI was compared with pseudo-continuous arterial spin labeling (pCASL).
  
  
  RESULTS
  For segmented grey matter (GM) regions of interests (ROIs), pCASL-based CBF was 63 ± 11 ml/(min 100 g) (mean ± SD). Nominal CBF from non-calibrated DSC-MRI was 277 ± 61 ml/(min 100 g), while calibrations resulted in 56 ± 23 ml/(min 100 g) (Bookend) and 52 ± 16 ml/(min 100 g) (VASO). Calibration tended to eliminate the overestimation, although the repeatability was generally moderate and the correlation between calibrated DSC-MRI and pCASL was low (r < 0.25). However, using GM instead of WM ROIs for extraction of CFs resulted in improved repeatability.
  
  
  CONCLUSIONS
  Both calibration approaches provided reasonable absolute levels of GM CBF, although the calibration methods suffered from low signal-to-noise ratio, resulting in weak repeatability and difficulties in showing high degrees of correlation with pCASL measurements.
authors.affiliation: Department of Medical Radiation Physics, Lund University, Lund University Hospital, 22185, Lund, Sweden, Emelie.Lindgren@med.lu.se.
authors.forename: Emelie
authors.initials: E
authors.lastname: Lindgren
authors.forename: Ronnie
authors.initials: R
authors.lastname: Wirestam
authors.forename: Karin
authors.initials: K
authors.lastname: Markenroth Bloch
authors.forename: André
authors.initials: A
authors.lastname: Ahlgren
authors.forename: Matthias J P
authors.initials: MJ
authors.lastname: van Osch
authors.forename: Danielle
authors.initials: D
authors.lastname: van Westen
authors.forename: Yulia
authors.initials: Y
authors.lastname: Surova
authors.forename: Freddy
authors.initials: F
authors.lastname: Ståhlberg
authors.forename: Linda
authors.initials: L
authors.lastname: Knutsson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001783:Blood Flow Velocity / Q000502:physiology; D001810:Blood Volume / Q000502:physiology*; D001811:Blood Volume Determination / Q000379:methods* / Q000592:standards; D001921:Brain / Q000033:anatomy & histology / Q000502:physiology; D002138:Calibration; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D016247:Information Storage and Retrieval / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013113:Spin Labels
chemical_list: D013113:Spin Labels