Myocardial Characterization on CT: Late Iodine Enhancement and Extracellular Volume

Myocardial tissue characterization is fundamental in diagnosing, treating, and managing various cardiac diseases. In recent years, cardiac computed tomography (CCT) emerged as a valuable alternative to cardiac magnetic resonance (CMR) for myocardial tissue characterization, with the possibility to detect myocardial scar and quantify the extracellular volume fraction in a single CT study with the advantage of combined coronary arteries evaluation, shorter scanning time, and less susceptibility to device artifacts compared to CMR. However, CCT is typically affected by a lower contrast-to-noise ratio and potentially increased radiation exposure. Therefore, a deep understanding of the available technology and the strategies for acquisition optimization is of fundamental importance to improve image quality and accuracy, while minimizing radiation exposure. This review summarizes principles of myocardial characterization on CCT, acquisition protocols according to the different technologies available including the dual-energy CT and the innovative photon-counting detector CT, and setting of clinical utility.