Investigating the magnetic susceptibility properties of fresh human blood for noninvasive oxygen saturation quantification

Abstract

Quantification of blood oxygen saturation on the basis of a measurement of its magnetic susceptibility demands knowledge of the difference in volume susceptibility between fully oxygenated and fully deoxygenated blood (Δπdo). However, two very different values of Δπdo are currently in use. In this work we measured Δπdo as well as the susceptibility of oxygenated blood relative to water, Δπoxy, by MR susceptometry in samples of freshly drawn human blood oxygenated to various levels, from 6 to 98% as determined by blood gas analysis. Regression analysis yielded 0.273 ± 0.006 and -0.008 ± 0.003 ppm (cgs) respectively, for Δπ do and Δπoxy, in excellent agreement with previous work by Spees et al. (Magn Reson Med 2001;45:533-542). Copyright © 2011 Wiley Periodicals, Inc.