Dynamic changes in the cerebral metabolic rate of O2 and oxygen extraction ratio in event-related functional MRI.
Dynamic changes in the cerebral metabolic rate of oxygen (CMRO(2)) and oxygen extraction ratio (OER) in an event-related functional MRI (ER-fMRI) were measured in this study. Six subjects participated in this study at a magnetic field of 1.9 T. Cerebral blood flow (CBF) and blood oxygenation level-dependent (BOLD) changes were acquired during the brief visual stimulation, and the corresponding changes in CMRO(2) and OER were then determined. The results showed that the maximum relative changes in CMRO(2) and OER were about 10.36 +/- 0.85 and -6.54 +/- 0.55%, respectively, while the maximum changes in CBF and BOLD were approximately 17.35 +/- 1.37 and 1.03 +/- 0.06%, respectively. The CBF, CMRO(2), and OER changes reach their maximum approximately 1 s earlier than the BOLD signal change (4.15 +/- 0.21, 4.16 +/- 0.21, and 4.17 +/- 0.21 s vs 5.12 +/- 0.24 s after stimulation, P < 0.05).
Feng
Ching-Mei
CM
Research Imaging Center, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA.
Liu
Ho-Ling
HL
Fox
Peter T
PT
Gao
Jia-Hong
JH
D001143:Arousal / Q000502:physiology; D001921:Brain / Q000098:blood supply*; D004734:Energy Metabolism / Q000502:physiology*; D005071:Evoked Potentials / Q000502:physiology; D005074:Evoked Potentials, Visual / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008432:Mathematical Computing; D010101:Oxygen Consumption / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology*; D012039:Regional Blood Flow / Q000502:physiology; D014793:Visual Cortex / Q000098:blood supply