• Cardiac magnetic resonance (CMR) imaging
• Acute myocardial infarction

Today, cardiovascular MRI (CMR) is widely used for diagnosis and therapeutic decision making in the setting of different cardiac diseases. CMR allows to analyse anatomical and functional parameters, and enables a non-invasive, accurate and repeatable assessment of changes in myocardial tissue. For example, contrast-enhanced CMR techniques such as late gadolinium enhancement (LGE) imaging enable an accurate, however, unspecific detection of myocardial damage, caused by myocardial infarction (MI). In addition, T2 and T2*-weighted CMR techniques allow to detect myocardial oedema as well as myocardial haemorrhage (in case of acute MI) and thereby provide additional information on infarct pathology and prediction of adverse outcome—at least in some cases.

Regarding the initiation of timely and adequate therapy, diagnosis of myocardial inflammation in the early phase of heart disease—before the occurrence of structural changes in the myocardium—is crucial. Unfortunately, T2-weighted CMR techniques that promise to depict myocardial oedema as the first morphological change in the sequence of events have a limited sensitivity, and are questioned with regard to their diagnostic value by some groups.1 Also novel T2-mapping techniques promise an improved diagnostic yield, neither LGE-based imaging nor T2- and T2*-weighted imaging do allow a direct visualisation of infiltrating macrophages in the infarcted myocardium, but rather depict myocardial tissue changes that are ‘associated’ with or the consequence of ongoing myocardial inflammation and healing. Hence, new and more specific CMR tools are needed to improve both early diagnosis and specificity of diagnosis.

From a clinical point of view, the opportunity to directly image infiltrating macrophages in the infarcted myocardium will be of broad diagnostic as well as therapeutic value since the extent and degree of myocardial disease might be monitored more accurately and the therapeutic success be assessed more appropriately.2 In this context, two distinct phases in the process of infarct healing were described recently3: …