Cardiac synchronization magnetic resonance imaging

TLDR: In this article, a conditioning pulse trigger is used to generate a conditioning inversion or saturation pulse at a time selected in accordance with the predicted R-wave (40 n-1 ) of one cardiac cycle.

Abstract: A cardiac monitor (62, 64) monitors the cardiac cycles of a patient in an examination region (10). Each cardiac cycle includes an R-wave (40) at the beginning of the end-diastole. A conditioning pulse trigger (74) enables a preconditioning pulse control (34) to generate a conditioning pulse (42) at a time selected in accordance with the R-wave (40 n-1 ) of one cardiac cycle. More specifically, an R-wave predictor (72) predicts when the next R-wave (40 n ) will occur and the conditioning pulse trigger enables the application of the conditioning pulse (42 n ) a selected duration before the next predicted R-wave (40 n ). An imaging sequence trigger (78) enables an image sequence controller (24) to start an imaging sequence in an imaging window (44 n ) in conjunction with the R-wave (40 n ). Preferably, the imaging sequence starts immediately with the R-wave (40 n ) such that the end-diastole stage of the heart is imaged. In this manner, a conditioning pulse, such as an inversion pulse or a saturation pulse, is applied in one cardiac cycle to affect the imaging sequence in the next cardiac cycle. The application of the preconditioning pulse is timed such that the longitudinal magnetization of the blood (54) is near zero (56) during the imaging sequence while the transverse magnetization of cardiac tissue (52) has substantially recovered by the imaging sequence.