Abstract 10659: CMR T1 Mapping at 3T Characterizes the Extent of Acute Ischemic Myocardial Injury: Comparison to Standard Techniques
Introduction: Due to the dynamic nature of changes within the acutely ischemic myocardium, the assessment of irreversible and reversible injury by cardiovascular magnetic resonance (CMR) techniques such as late gadolinium enhancement (LGE) and oedema imaging (T2W) may be problematic. New techniques allowing for characterization of the myocardium such as quantitative non contrast T1-mapping are needed. We sought to assess the diagnostic accuracy of T1-mapping in patients presenting with myocardial infarction (MI) and whether it can quantify the extent of injury when compared to techniques such as LGE and T2W imaging.
Methods and Results: Two groups of patients [32 with ST elevation MI (STEMI) and 9 with non STEMI (NSTEMI)] underwent 3T CMR 24 hrs after chest pain onset. STEMI patients underwent primary percutanous coronary intervention prior to CMR. Troponin I levels at 12 hrs were 38 ± 15 µg/L in STEMI and 9 ± 7 µg/L in NSTEMI (P<0.01). T2W, Shortened Modified Look-Looker Inversion recovery (ShMOLLI) T1 mapping and LGE matching short axis slices were obtained.
The segmental damaged fraction, by T2W and LGE and the segmental average T1 values were obtained using a 6 segment model per slice.
In STEMI patients, the diagnostic performance of ShMOLLI was equal to T2W in detecting acute myocardial injury as derived from LGE. However, in NSTEMI, ShMOLLI improved detection of myocardial injury significantly compared to T2W (P=0.004). Also, a significant relationship between the segmental extent of myocardial injury by LGE or T2W and increasing values of T1 was found (P<0.01) (Fig.).
Conclusions: 1) In MI patients, non contrast ShMOLLI T1 mapping has equal (STEMI) or superior (NSTEMI) diagnostic accuracy in detecting myocardial injury compared toT2W; 2) increasing T1 values allow assessment of the extent of segmental damaged fraction without the need for contrast agent. Quantitative T1 mapping is a powerful CMR technique for assessment of acute ischemic myocardial injury
- © 2011 by American Heart Association, Inc.