Assessment of hemodynamic response during focal neural activity in human using bolus tracking, arterial spin labeling and BOLD techniques.
In this study, the hemodynamic response and changes in oxidative metabolism during functional activation were measured using three functional magnetic resonance imaging (fMRI) techniques: the blood oxygenation level-dependent (BOLD) technique, flow-sensitive alternating inversion recovery (FAIR), and bolus tracking (BT) of an MR contrast agent. With these three techniques we independently determined changes in BOLD signal, relative cerebral blood flow (rCBF), and cerebral blood volume (rCBV) associated with brain activation in eight healthy volunteers. In the motor cortex, the BOLD signal increased by 1.8 +/- 0.5%, rCBF by 36.3 +/- 8.2% (FAIR), and 35.1 +/- 8.6% (BT), and rCBV by 19.4 +/- 4.1% (BT) in response to simultaneous bilateral finger tapping. In the visual cortex, BOLD signal increased by 2.6 +/- 0.5%, rCBF by 38.5% +/- 7.6 (FAIR), and 36.9 +/- 8.8% (BT), and rCBV by 18.8 +/- 2.8% (BT) during flickering checkerboard stimulation. Comparing the experimentally measured rCBV with the calculated rCBV using Grubb's power-law relation, we conclude that the use of power-law relationship results in systematic underestimate of rCBV.
Li
T Q
TQ
Department of Radiology, Stanford University School of Medicine, California 94305, USA.
Haefelin
T N
TN
Chan
B
B
Kastrup
A
A
Jonsson
T
T
Glover
G H
GH
Moseley
M E
ME
D000328:Adult; D001810:Blood Volume / Q000502:physiology; D001921:Brain / Q000378:metabolism / Q000502:physiology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003287:Contrast Media / Q000493:pharmacokinetics; D005385:Fingers / Q000502:physiology; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008959:Models, Neurological; D009044:Motor Cortex / Q000098:blood supply; D009068:Movement / Q000502:physiology; D010084:Oxidation-Reduction; D013113:Spin Labels; D014793:Visual Cortex / Q000098:blood supply
D003287:Contrast Media; D013113:Spin Labels