Flip Angle Strategies for Multiphase DENSE

Introduction: Displacement ENcoding with Stimulated Echoes (DENSE) is a method to acquire myocardial displacement during the cardiac cycle. Spatial position is encoded and stored in the longitudinal magnetization at one point in time, and then read out later in the cardiac cycle, thus directly obtaining the displacement during that interval. The stimulated echo experiment results in a different signal behavior compared to conventional imaging. In conventional cine imaging, longitudinal relaxation turns previously excited signal into usable signal later during the same cardiac cycle. In DENSE, the the longitudinal relaxation consumes the stimulated echo and turns it into an artifact generating echo during the rest of the cardiac cycle. Only at the time of the next position encoding, typically the next R-wave, is the signal usable again. Furthermore, the excitation also consumes the stimulated echo.