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

Abstract

Recently the blood oxygenation level-dependent (BOLD)-related T(2)* 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 T(2) as a function of the parameters above and the echotime. An analytical relationship between T(2) and T(2)* relaxation is derived. The dependence of T(2) on diffusion, echo time, and blood oxygenation is congruent with simulation and experimental data. Magn Reson Med 42:1004-1010, 1999.