Figure 1.

(a) The schematic of the proposed sequence. Multiple single-shot images of the heart are acquired using ECG-triggering, following T₂prep of different echo lengths, TE_T2P. Between each image, a 6 second rest period (with no RF pulses) is applied to allow for full re-growth of the myocardium signal. An image, I_SAT, is acquired directly after a saturation pulse to simulate the effect of a very long T₂prep echo time (i.e. T₂prep = ∞) for improved estimation of the third parameter in the 3-parameter fit. (b) Flowchart for the proposed navigator (NAV)-gated acquisition scheme, The NAV is placed before the T₂prep. If the NAV signal preceding the acquisition of the k^th image is outside the gating window, no T₂prep or imaging pulses are applied, leaving the magnetization undisturbed, and the acquisition of this image is repeated in the next R-R interval. If the NAV signal is within the gating window, the image with the desired T₂prep time is acquired, followed by a 6 second rest period for magnetization recovery. (c) An example of the rejection-reacquisition scheme for a T₂-prepared image. (d) An example of the acquisition of a saturation-prepared image, which immediately follows the T₂-prepared image without any rest periods, and where the NAV is placed before the saturation pulse.