Current T 1 and T 2 mapping techniques applied with simple thresholds cannot discriminate acute from chronic myocadial infarction on an individual patient basis: a pilot study

Background Studying T 1 - and T 2 -mapping for discrimination of acute from chronic myocardial infarction (AMI, CMI). Methods Eight patients with AMI underwent CMR at 3 T acutely and after >3 months. Imaging techniques included: T 2 -weighted imaging, late enhancement (LGE), T 2 -mapping, native and post-contrast T 1 -mapping. Myocardial T 2 - and T 1 -relaxation times were determined for every voxel. Abnormal voxels as defined by having T 2 - and T 1 -values beyond a predefined threshold (T 2 > 50 ms, native T 1 > 1250 ms and post-contrast T 1 < 350 ms) were highlighted and compared with LGE as the reference. Results Abnormal T 2 -relaxation times were present in the voxels with AMI (=> delete acute infarction; unfortunately this is not possible in your web interface) acute infarction only in half of the subjects. Abnormal T 2 -values were also present in subjects with CMI, thereby matching the chronically infarcted territory in some. Abnormal native T 1 times were present in voxels with AMI in 5/8 subjects, but also remote from the infarcted territory in four. In CMI, abnormal native T 1 values corresponded with infarcted voxels, but were also abnormal remote from the infarcted territory. Voxels with abnormal post-contrast T 1 -relaxation times agreed well with LGE in AMI and CMI. Conclusions In this pilot-study, T 2 - and T 1 -mapping with simple thresholds did not facilitate the discrimination of AMI and CMI.