title: Brain mapping with functional MR imaging: comparison of gradient-echo--based exogenous and endogenous contrast techniques.
abstract: OBJECTIVE
  To compare directly the two most widely used methods of functional magnetic resonance (MR) imaging--dynamic contrast material-enhanced MR imaging and blood oxygenation level-dependent (BOLD) MR imaging.
  
  
  METHODS
  Five healthy volunteers underwent dynamic contrast-enhanced and BOLD MR imaging with a conventional 1.5-T MR unit during visual stimulation and a dark control state. BOLD studies were performed with a gradient-echo sequence, and dynamic MR imaging was performed with an echo-shifted gradient-echo sequence after intravenous administration of a bolus of gadopentetate dimeglumine.
  
  
  RESULTS
  A significantly greater percentage signal change was found with dynamic MR imaging than with the BOLD technique. The extent of area activated was also significantly greater.
  
  
  CONCLUSIONS
  With standard clinical imagers and these gradient-echo-based techniques, greater percentage activation and area of activation can be achieved with dynamic MR imaging than with BOLD MR imaging.
authors.affiliation: Laboratory of Diagnostic Radiology Research, National Institutes of Health, Bethesda, MD 20892.
authors.forename: V S
authors.initials: VS
authors.lastname: Mattay
authors.forename: D R
authors.initials: DR
authors.lastname: Weinberger
authors.forename: F A
authors.initials: FA
authors.lastname: Barrios
authors.forename: G S
authors.initials: GS
authors.lastname: Sobering
authors.forename: K J
authors.initials: KJ
authors.lastname: Kotrla
authors.forename: P
authors.initials: P
authors.lastname: van Gelderen
authors.forename: J H
authors.initials: JH
authors.lastname: Duyn
authors.forename: R H
authors.initials: RH
authors.lastname: Sexton
authors.forename: C T
authors.initials: CT
authors.lastname: Moonen
authors.forename: J A
authors.initials: JA
authors.lastname: Frank
mesh_terms: D001921:Brain / Q000033:anatomy & histology* / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology; D003287:Contrast Media; D004338:Drug Combinations; D019786:Gadolinium DTPA; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008536:Meglumine; D009942:Organometallic Compounds; D004369:Pentetic Acid / Q000031:analogs & derivatives; D010775:Photic Stimulation
chemical_list: D003287:Contrast Media; D004338:Drug Combinations; D009942:Organometallic Compounds; D008536:Meglumine; D004369:Pentetic Acid; D019786:Gadolinium DTPA