Native T 1-mapping detects acute myocardial infarction without application of gadolinium contrast agents

Objective: This study aimed to demonstrate T1-mapping how to display the patterns of myocardial injury and to quantify myocardial involvement in acute myocardial infarction (AMI) without application of contrast agents. Methods: Total 50 patients with suspected AMI (median 3 days from presentation) enrolled as myocardial infarction group and 20 as normal controls group. Then, analysis of these patients were performed, including: lesion myocardial T2 signal intensity (SI) ratio compared to remote normal myocardium, non-contrast myocardial T1 times, left ventricular function including ejection fraction, myocardial mass and left ventricular volume, and areas of injury by T2W, T1-mapping and LGE. Results: Compared with normal controls, AMI patients showed more edema (myocardial T2 SI ratio 1.85 ± 0.30 vs 1.55 ± 0.14, P < 0.05), higher mean non-contrast myocardial T1 (1220 ± 50 ms vs 981 ± 23 ms) and more areas of injury as detected by T2W (median 15%), T1 values (median 28%), and LGE (median 12%). However, no significant difference was identified in LV mass and ventricular volume (P > 0.05). With T1 > 1300 ms (sensitivity 90%, specificity 75%), detected significantly larger areas of involvement were significantly detected compared with T2W and LGE imaging. T1-mapping significantly improved the diagnostic confidence which cannot detected using T2W or LGE). Using incremental thresholds, T1-mapping can display the patterns of injury typical of acute myocardial infarction. Conclusion: Native T1-mapping as a novel technique for detecting the patterns in acute myocardial infarction without application of contrast medium. Compared to T2W and LGE imaging, T1-mappng detects additional areas of myocardial tissues, and offers significant diagnostic value in AMI detection.