Quantification of both the area-at-risk and acute myocardial infarct size in ST-segment elevation myocardial infarction using T1-mapping

Figures

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  Fig. 1. The MagIR and PSIR output from the MOLLI T1-mapping prototype. This is an illustration of the 2 additional outputs (with TI 200 ms to 975 ms) that were obtained from the MOLLI T1-mapping prototype for a patient with an acutely reperfused inferior STEMI. For synthetic MagIR LGE, the image with the optimal TI was manually chosen retrospectively as illustrated by the red square. For the synthetic PSIR LGE, the corresponding image from the PSIR output was chosen (red square) and was manually windowed if required

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  Fig. 2. Representative examples of the T2 and native T1 maps showing the edema-based AAR and the corresponding LGE on the conventional, synthetic and post-contrast T1 maps. Patients A and C suffered from an acute anterior STEMI and Patient B suffered from an acute inferior STEMI – all were treated by PPCI. The black arrows indicate the territory of the edema-based AAR on the T2 and native T1 maps and the red arrows indicate the territory of the subendocardial MI (of different transmural extents) on the conventional and synthetic LGE images and post-contrast T1 maps. All these patients had significant myocardial salvage but the areas of abnormality on the T2 and native T1 maps extended beyond the corresponding MI territory, indicating edema in the salvaged myocardium

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  Fig. 3. Comparison of MI size and edema-based AAR quantified by the different techniques. This figure illustrates MI size by the conventional LGE, synthetic LGE and post-contrast T1-mapping and edema-based AAR by T2 and T1-mapping. NS denotes no statistical difference and * denote P < 0.05. Data presented as mean ± 95% CI

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  Fig. 4. Comparison of the edema-based AAR by T2 and native T1-mapping. There was an excellent correlation (a) and minimal bias (b) in edema-based AAR delineated by T2-mapping versus native T1-mapping

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  Fig. 5. Comparison of MI size by different methods against the reference standard. These are the correlations (a-d) and Bland-Altman analyses (e-h) of MI size by conventional LGE against each of the 4 other techniques (synthetic MagIR LGE, synthetic PSIR LGE, post-contrast T1 2-SD and post-contrast T1 Otsu)

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  Fig. 6. a-d Duration of the CMR scan. a and b illustrate the duration for a comprehensive STEMI CMR acquisition protocol providing data on edema-based AAR, intramyocardial hemorrhage, microvascular obstruction, MI size and ECV and on average takes around one hour to acquire. Based on the results from this study, T1-mapping may allow T2-mapping and LGE to be omitted thereby shortening the scanning time by 15–20 min. c and d illustrates the options of either doing T2-mapping and post-contrast T1-mapping or native T1 mapping and post-contrast T1 mapping depending on the research question