Clinical Recommendations for CMR Mapping of T1, T2, T2* and Extracellular Volume
A consensus statement by the Society for Cardiovascular Magnetic Resonance (SCMR) endorsed by the European Association for Cardiovascular Imaging (EACVI) has recently been published in the Journal of Cardiovascular Magnetic Resonance. This document provides recommendations for clinical and research applications of CMR myocardial T1, T2, T2*, and ECV mapping. The authors cite published evidence when available and provide expert consensus where incomplete. They recognized a priori that multiple methodologies for CMR parametric mapping do and should exist, with continued evolution and residual imperfections. Despite these limitations, abundant evidence demonstrates that parametric mapping appears robust under many conditions in its present form. The authors also make analogy to another key cardiac imaging biomarker, the left ventricular ejection fraction (LVEF), where measurement variations persist within and across modalities, yet the yield of biological information is sufficient to diagnose disease, guide and monitor treatment, and to predict outcome. CMR parametric mapping goes beyond nonspecific functional surrogate markers of cardiovascular disease such as LVEF. Rather, CMR parametric mapping offers the potential to examine specific disease pathways that affect myocardial tissue composition. View full article >>
The body of evidence supporting the beneficial utilization of cardiovascular magnetic resonance (CMR) has grown significantly over the last decade. A recent analysis exhibited that CMR is already incorporated into 88% of the guidelines published by the European Society of Cardiology, in many as specific recommendations, and in most at least by mention in
the text passages. Hence, CMR co
mmonly plays a role in evidence based diagnostic and therapeutic pathways, and can even be considered mandatory in a number of clinical scenarios. The guidelines published by the American Heart Association (AHA) and the American College of Cardiology (ACC) are often used as the basis for clinical decision making and therefore can have a high impact on utilization of technology such as CMR. This analysis systematically summarizes the representation of CMR in the AHA/ACC guidelines to stimulate the discussion about future needs for training, distribution of equipment, and reimbursement of CMR worldwide. View full article >>
Multiple studies have suggested that acute myocardial infarct imaging by CMR late gadolinium enhancement (LGE) may be problematic in the early period due to overestimation of true infarct size, a phenomenon attributed to a peri-infarct zone of edema and cellular injury known as the area at risk (AAR). The underestimation of viable tissue by LGE has real clinical implications, given that this parameter may be used to guide revascularization strategies. To that end, many different methodologies have been explored to hone in on predicting true infarct size (IS), including T1 and T2-weighted imaging, T1 maps, extracellular volume (ECV) mapping, LGE and the myocardial salvage index. ECV mapping has certain advantages over semi-automated thresholding methods, specifically that it is quantitative and also reflects more specifically extracellular matrix expansion than the other techniques. View full article>>