The relationship between the BOLD-induced T-2 and T-2*: A theoretical approach for the vasculature of myocardium

Recently the blood oxygenation level-dependent (BOLD)related T*(2) of myoca rdium 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 experime nts that gives myocardiaI T-2 as a function of the parameters above and the echotime. An analytical relationship between T-2 and T*(2) relaxation is d erived. The dependence of T-2 on diffusion, echo time, and blood oxygenatio n is congruent with simulation and experimental data. (C) 1999 Wiley-Liss, Inc.