On the Origin of Myocardial Edema Contrast in T2-STIR Images

Introduction Acute myocardial infarcts (AMI) are typically discriminated with T2-weighted short TI inversion recovery (STIR) with turbo spin echo (TSE) readouts [1], albeit with limited specificity [2]. Guided by the association that T2-STIR images identify AMI territories on the basis of edema-related T2 changes, even some of the recently proposed improvements [2,3] have relied on preferential sensitization of magnetization to T2weighting. However, whether T2-STIR imaging itself may also be sensitive to other sources of image contrast have not been fully investigated. We hypothesize that in addition to T2-weighting, edema detection with T2-STIR imaging has substantial weighting from proton density (PD) changes.