One-click co-registered T2 mapping and dual black- and bright-blood late gadolinium enhancement MRI for comprehensive assessment of myocardial injury after acute STEMI.

Aims: In acute ST-segment elevation myocardial infarction, ischaemia and reperfusion lead to a cascade of myocardial injury that can be characterized by cardiac magnetic resonance (CMR) imaging, including coagulation necrosis, oedema, papillary muscle damage, microvascular obstruction, and intramyocardial haemorrhage. Conventional CMR protocols require multiple sequences to be performed and complicated analysis. This study evaluates SPOT-MAPPING, a sequence that acquires co-registered T2 maps and dual bright- and black-blood late gadolinium enhancement (LGE) images in a single scan.

Methods And Results: SPOT-MAPPING employs a single-shot, ECG-triggered 2D sequence alternating between bright- and black-blood LGE imaging with varying T2 weightings. We prospectively enrolled 20 STEMI patients undergoing CMR at 1.5 T within 4-7 days post-emergent coronary intervention. SPOT-MAPPING's segmentation times and reproducibility of myocardial injury markers (oedema, scar size, transmurality, papillary muscle damage) were assessed against conventional T2 mapping and phase-sensitive inversion recovery (PSIR). SPOT-MAPPING halved left ventricular wall segmentation time (∼3 min) while maintaining high reproducibility for oedema, scar size, and transmurality (ICC > 0.8). It improved papillary muscle damage detection over PSIR (8 vs. 3 patients) and showed comparable T2 values with conventional T2 mapping (remote: 45.0 ± 3.6 ms vs. 45.9 ± 3.7 ms, = 0.746; oedema: 67.6 ± 10.3 ms vs. 71.8 ± 8.6 ms, = 0.373). Agreement with PSIR for scar quantification was strong (mean bias: volume +1.5 mL, size +2.9%, transmurality +2.8%). SPOT-MAPPING demonstrated higher inter- and intraobserver reproducibility for scar size as a percentage of oedema volume compared with PSIR combined with conventional T2 mapping (ICC = 0.98 vs. 0.89 and 0.93 vs. 0.85).

Conclusion: SPOT-MAPPING offers a time-efficient and reproducible CMR method for myocardial injury assessment post-STEMI.