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Quantitative fMRI

  • N. P. Blockley
  • V. E. M. Griffeth
  • A. B. Simon
  • R. B. Buxton
Chapter
Part of the Biological Magnetic Resonance book series (BIMR, volume 30)

Abstract

Blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (MRI) has proven to be a powerful and sensitive tool for noninvasively detecting neural activity changes in the brain. However, the complex relationship between local blood flow, blood volume and oxygen metabolism that underlies the BOLD signal has proven to be problematic when comparing BOLD responses across subjects, imaging sites and time. Due to this complexity it is possible to generate similar BOLD responses with very different underlying changes in blood flow, blood volume and oxygen metabolism. Tools to quantify the BOLD signal in terms of oxidative metabolism have applications beyond improving the accuracy of functional MRI, for example in the study of pharmacological agents, ageing, or disease. The focus of this chapter is to consider how oxygen metabolism may be measured along with how it affects the BOLD signal. The calibrated BOLD technique is discussed for the measurement of changes in oxygen metabolism, as well as two promising techniques for quantifying baseline oxygen metabolism: T2 relaxation under spin tagging (TRUST) and quantitative BOLD (qBOLD). Current issues with each of these techniques are examined and future directions for this research field are considered.

Keywords

Bold Signal Bold Response Oxygen Extraction Fraction Magnetic Resonance Signal Bold Signal Change 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer New York 2015

Authors and Affiliations

  • N. P. Blockley
    • 1
    • 4
  • V. E. M. Griffeth
    • 2
  • A. B. Simon
    • 2
  • R. B. Buxton
    • 1
    • 3
  1. 1.Department of Radiology, Center for Functional MRIUniversity of California San DiegoLa JollaUSA
  2. 2.Department of Bioengineering and Medical Scientist Training ProgramUniversity of California San DiegoLa JollaUSA
  3. 3.Kavli Institute for Brain and MindUniversity of California San DiegoLa JollaUSA
  4. 4.FMRIB Centre, Nuffield Department of Clinical NeurosciencesUniversity of Oxford, John Radcliffe HospitalOxfordUK

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