Clinical indications for cardiovascular magnetic resonance.

### Learning objectives Cardiovascular magnetic resonance (CMR) is a highly versatile non-invasive and non-ionising multi-parametric imaging technique. Within the multimodality imaging setting of current clinical practice, CMR provides relative strengths in different aspects of the clinical work-up (table 1). It has become the reference standard for the evaluation of cardiac volumes and function. Its perfusion module has positioned itself as an accurate imaging stress test with indications for the proof of haemodynamically significant coronary artery disease (CAD) in all major international guidelines. Nonetheless, its unique advantage and distinctive feature resides in its tissue characterisation capabilities, including late gadolinium enhancement (LGE) for visualisation of regional replacement scar, T1 mapping for diffuse myocardial fibrosis and T2 mapping for myocardial oedema/inflammation. This in vivo depiction of myocardial tissue characteristics broadens its diagnostic power beyond the dichotomy of the presence or absence of a particular disease (eg, CAD) to include several options to explain a patient’s clinical picture (eg, myocarditis, Takotsubo, pericarditis, microvascular disease), allowing for guidance of an individualised and optimised therapy.1 View this table: Table 1 Strength of each cardiac imaging technique European Society of Cardiology (ESC) guidelines generally consider CMR as the best alternative cardiac imaging modality for patients with non-diagnostic echocardiographic studies.2–5 This review demonstrates, however, many situations where it seems appropriate to consider CMR as a first-line tool to differentiate the various underlying aetiologies of an abnormal finding or presentation and guide individual therapy. In past years the use of CMR was restricted to historically established indications such as the evaluation of complex …