title: Contrast agent dose effects in cerebral dynamic susceptibility contrast magnetic resonance perfusion imaging.
abstract: OBJECTIVE
  To study the contrast agent dose sensitivity of hemodynamic parameters derived from brain dynamic susceptibility contrast MRI (DSC-MRI).
  
  
  METHODS
  Sequential DSC-MRI (1.5T gradient-echo echo-planar imaging using an echo time of 61-64 msec) was performed using contrast agent doses of 0.1 and 0.2 mmol/kg delivered at a fixed rate of 5.0 mL/second in 12 normal subjects and 12 stroke patients.
  
  
  RESULTS
  1) Arterial signal showed the expected doubling in relaxation response (DeltaR2*) to dose doubling. 2) The brain signal showed a less than doubled DeltaR2* response to dose doubling. 3) The 0.2 mmol/kg dose studies subtly underestimated cerebral blood volume (CBV) and cerebral blood flow (CBF) relative to the 0.1 mmol/kg studies. 4) In the range of low CBV and CBF, the 0.2 mmol/kg studies overestimated the CBV and CBF compared with the 0.1 mmol/kg studies. 5) The 0.1 mmol/kg studies reported larger ischemic volumes in stroke.
  
  
  CONCLUSIONS
  Subtle but statistically significant dose sensitivities were found. Therefore, it is advisable to carefully control the contrast agent dose when DSC-MRI is used in clinical trials. The study also suggests that a 0.1 mmol/kg dose is adequate for hemodynamic measurements.
authors.affiliation: Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA. jralger@ucla.edu
authors.forename: Jeffry R
authors.initials: JR
authors.lastname: Alger
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Schaewe
authors.forename: Tom C
authors.initials: TC
authors.lastname: Lai
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Frew
authors.forename: Paul M
authors.initials: PM
authors.lastname: Vespa
authors.forename: Maria
authors.initials: M
authors.lastname: Etchepare
authors.forename: David S
authors.initials: DS
authors.lastname: Liebeskind
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Saver
authors.forename: S Chelsea
authors.initials: SC
authors.lastname: Kidwell
mesh_terms: D001783:Blood Flow Velocity; D001921:Brain / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology*; D002545:Brain Ischemia / Q000473:pathology / Q000503:physiopathology*; D003287:Contrast Media / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D017352:Echo-Planar Imaging / Q000379:methods*; D019786:Gadolinium DTPA / Q000008:administration & dosage*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA