Comparison of blood oxygenattion and cerebral blood flow effect in fMRI: Estimation of relative oxygen consumption change

The most widely‐used functional magnetic resonance imaging (fMRI) technique is based on the blood oxygenation level dependent (BOLD) effect, which requires at least partial uncoupling between cerebral blood flow (CBF) and oxygen consumption changes during increased mental activity. To compare BOLD and CBF effects during tasking, BOLD and flowsensitive alternating inversion recovery (FAIR) images were acquired during visual stimulation with red goggles at a frequency of 8 Hz in an inteerleaved fashion. With the FAIR technique, absolute and relative CBF changes were determined. Relative oxygen consumption changes cdan be estimated using the BOLD and relative CBF changes. In gray matter areas in the visual cortex, absolute and relative CBF changes in humans during photic stimulation were 31 ± 11 SD ml/100 g tissue/min and 43 ± 16 SD % (n =12), respectively, while the relative oxygen consumption change was close to zero. These findings agree extremely well with previouse results using positron emission tomography. The BOLD signal change is not linearly correlated with the relative CBF increase across subjects and negatively correlates with the oxygen consumption change. Caution should be exercised when interpreting the BOLD percent change as a quantitative index of the CBF change, especially in inter‐subject comparisons.

[1]  S. Ogawa.  Brain magnetic resonance imaging with contrast-dependent oxygenation , 1990 .

[2]  M. Raichle,et al.  The Effects of Changes in PaCO2 Cerebral Blood Volume, Blood Flow, and Vascular Mean Transit Time , 1974, Stroke.

[3]  M. Raichle,et al.  Focal physiological uncoupling of cerebral blood flow and oxidative metabolism during somatosensory stimulation in human subjects. , 1986, Proceedings of the National Academy of Sciences of the United States of America.

[4]  Seong-Gi Kim.  Quantification of relative cerebral blood flow change by flow‐sensitive alternating inversion recovery (FAIR) technique: Application to functional mapping , 1995, Magnetic resonance in medicine.

[5]  E. Haacke,et al.  Identification of vascular structures as a major source of signal contrast in high resolution 2D and 3D functional activation imaging of the motor cortex at l.5T preliminary results , 1993, Magnetic resonance in medicine.

[6]  S. Ogawa,et al.  Magnetic resonance imaging of blood vessels at high fields: In vivo and in vitro measurements and image simulation , 1990, Magnetic resonance in medicine.

[7]  J H Duyn,et al.  Inflow versus deoxyhemoglobin effects in bold functional MRI using gradient echoes at 1.5 T , 1994, NMR in biomedicine.

[8]  S. Ogawa,et al.  Oxygenation‐sensitive contrast in magnetic resonance image of rodent brain at high magnetic fields , 1990, Magnetic resonance in medicine.

[9]  Ravi S. Menon,et al.  Intrinsic signal changes accompanying sensory stimulation: functional brain mapping with magnetic resonance imaging. , 1992, Proceedings of the National Academy of Sciences of the United States of America.

[10]  A. Kleinschmidt,et al.  Brain or veinoxygenation or flow? On signal physiology in functional MRI of human brain activation , 1994, NMR in biomedicine.

[11]  R. J. Seitz,et al.  Vibratory stimulation increases and decreases the regional cerebral blood flow and oxidative metabolism: a positron emission tomography (PET) study , 1992, Acta neurologica Scandinavica.

[12]  D. Tank,et al.  4 Tesla gradient recalled echo characteristics of photic stimulation‐induced signal changes in the human primary visual cortex , 1993 .

[13]  D Comar,et al.  Regional Cerebral Blood Flow and Oxygen Consumption in Human Aging , 1984, Stroke.

[14]  E C Wong,et al.  Processing strategies for time‐course data sets in functional mri of the human brain , 1993, Magnetic resonance in medicine.

[15]  A L Benabid,et al.  Functional MRI of the human brain: predominance of signals from extracerebral veins. , 1994, Neuroreport.

[16]  S G Kim,et al.  Perfusion imaging by a flow‐sensitive alternating inversion recovery (Fair) technique: Application to functional brain imaging , 1997, Magnetic resonance in medicine.

[17]  B. Rosen,et al.  Functional mapping of the human visual cortex by magnetic resonance imaging. , 1991, Science.

[18]  D. Tank,et al.  Brain magnetic resonance imaging with contrast dependent on blood oxygenation. , 1990, Proceedings of the National Academy of Sciences of the United States of America.

[19]  Xiaoping Hu,et al.  Potential pitfalls of functional MRI using conventional gradient‐recalled echo techniques , 1994, NMR in biomedicine.

[20]  G. Radda,et al.  Oxygenation dependence of the transverse relaxation time of water protons in whole blood at high field. , 1982, Biochimica et biophysica acta.

[21]  Jonathan D. Cohen,et al.  Improved Assessment of Significant Activation in Functional Magnetic Resonance Imaging (fMRI): Use of a Cluster‐Size Threshold , 1995, Magnetic resonance in medicine.

[22]  X. Hu,et al.  Fast interleaved echo‐planar imaging with navigator: High resolution anatomic and functional images at 4 tesla , 1996, Magnetic resonance in medicine.

[23]  S. Ogawa,et al.  The sensitivity of magnetic resonance image signals of a rat brain to changes in the cerebral venous blood oxygenation , 1993, Magnetic resonance in medicine.

[24]  D. Weinberger,et al.  Functional Mapping of Human Sensorimotor Cortex with 3D BOLD fMRI Correlates Highly with H215O PET rCBF , 1996, Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism.

[25]  G. Pawlik,et al.  Quantitative capillary topography and blood flow in the cerebral cortex of cats: an in vivo microscopic study , 1981, Brain Research.

[26]  A. Haase,et al.  Snapshot flash mri. applications to t1, t2, and chemical‐shift imaging , 1990, Magnetic resonance in medicine.

[27]  S G Kim,et al.  Accurate T1 determination from inversion recovery images: Application to human brain at 4 Tesla , 1994, Magnetic resonance in medicine.

[28]  S. Ogawa,et al.  BOLD Based Functional MRI at 4 Tesla Includes a Capillary Bed Contribution: Echo‐Planar Imaging Correlates with Previous Optical Imaging Using Intrinsic Signals , 1995, Magnetic resonance in medicine.

[29]  P E Roland,et al.  Does mental activity change the oxidative metabolism of the brain? , 1987, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[30]  C. D. Coryell,et al.  The Magnetic Properties and Structure of Hemoglobin, Oxyhemoglobin and Carbonmonoxyhemoglobin , 1936, Proceedings of the National Academy of Sciences.

[31]  M. Mintun,et al.  Nonoxidative glucose consumption during focal physiologic neural activity. , 1988, Science.

[32]  R. Turner,et al.  Dynamic magnetic resonance imaging of human brain activity during primary sensory stimulation. , 1992, Proceedings of the National Academy of Sciences of the United States of America.

[33]  A A Lammertsma,et al.  CMRO2 and CBF by the oxygen-15 inhalation technique. Results in normal volunteers and cerebrovascular patients. , 1981, European neurology.