Fig. 1
From: Respiratory motion-compensated high-resolution 3D whole-heart T1ρ mapping
Sequence diagram for the proposed free-breathing electrocardiogram (ECG)-triggered 3D T1ρ mapping acquisition. Acquisitions of two different T1ρ contrasts with 3D balanced steady-state free precession (bSSFP) readouts are shown. A saturation pulse (SAT) is used to reset the magnetization in each heartbeat. After a constant delay (TSR), T1ρ preparation (T1ρ prep) is performed followed by fat saturation pulse (FAT SAT), whereas 2D image navigators (iNAV) are acquired using the ramp-up preparation pulses of the bSSFP (a). The trigger delay is kept constant for all T1ρ preps (with different durations) by adjusting the time between ECG and SAT. An undersampled variable-density 3D Cartesian trajectory with spiral-like order is used for acceleration, spiral-like arms are rotated with golden angle step within and between T1ρ contrasts (b)