The relationship between the BOLD-induced T₂ and T: A theoretical approach for the vasculature of myocardium

Recently the blood oxygenation level–dependent (BOLD)-related T₂* of myocardium was derived as an analytical function of intracapillary blood volume, blood oxygenation, and nuclear spin diffusion. The basis of this approach was to approximate the diffusion-induced field fluctuations a nuclear spin is subjected to by strong collision dynamics, i.e., the field fluctuations are uncorrelated. The same analysis is now performed for spin echo experiments that gives myocardial T₂ as a function of the parameters above and the echotime. An analytical relationship between T₂ and T₂* relaxation is derived. The dependence of T₂ on diffusion, echo time, and blood oxygenation is congruent with simulation and experimental data. Magn Reson Med 42:1004–1010, 1999. © 1999 Wiley-Liss, Inc.