Recent studies demonstrate that hyperintense regions in T2-weighted images in acute myocardial infarction (AMI) reflect the presence of edema [1] and area at risk. Single-shot T2-prepared SSFP methods have been presented for T2-weighted imaging in AMI [2]. Here a segmented SSFP approach suitable for multi-slice, multi-echo imaging of the myocardium is presented.

Even with accelerated imaging methods the acquisition window for single-shot SSFP techniques can be long (>200-250 ms). A segmented SSFP method is proposed, allowing for shorter acquisition windows and a corresponding capability to acquire multiple slice locations per heart beat as illustrated in Fig 1. If the number of segments is limited, the entire acquisition can be repeated with different preparation durations (TE's) in a single breath-hold, enabling T2-mapping. Such a segmented approach presents a number of challenges:

To maximize T2 contrast while minimizing eddy current effects [3], an even-odd, centric phase encode ordering scheme was implemented.

To preserve the prepared T2 contrast across multiple slices an RF chopping scheme [4] consisting of two averages with an inversion pulse following the T2-preparation on even averages was implemented. This enables subtraction of contaminant signal that recovers with time constant T1.

To preserve in-slice signal integrity, in-slice signal is catalyzed prior to, and spoiled following, data acquisition to minimize cross-slice contamination.

Finally, fat saturation was integrated into the preparation interval [5] to reduce contributions of recovering fat signal.

T2 values are estimated using a 2-parameter exponential fit or a 3-parameter fit including baseline offset.

A segmented, T2-prepared, multi-slice, multi-echo imaging sequence is presented that can be applied to edema identification in AMI patients.