Cardiovascular magnetic resonance imaging in patients with acute myocardial infarction

Cardiovascular magnetic resonance imaging (CMR) is increasingly used in the daily practice of the clinical cardiologist. Technical advances in hardware and development of new software have led to major improvements in image quality, spatial and temporal resolution, and imaging speed, allowing the detailed assessment of the whole spectrum of cardiovascular disease. This article reviews the clinical applications of CMR in patients with acute myocardial infarction (AMI). ### Cine imaging Cine imaging forms the backbone of the CMR examination. It is used for the qualitative and quantitative assessment of myocardial anatomy and function, and, with the use of dobutamine stress, to evaluate ischaemia and viability (box 1). In addition, it may be used as an alternative technique to Doppler echocardiography for the evaluation of valvular heart disease. The standard cine pulse sequence is a breath-hold, steady state free precession (SSFP) sequence that provides optimal contrast between blood and myocardium (figure 1; see also supplemental videos 1 and 2). Current cine sequences use retrospective ECG gating, although prospective gating may be required in patients with irregular heart rhythm. When heart rhythm is notably irregular, as with complex ventricular ectopy, real time imaging without ECG gating will still allow the assessment of regional and global function, albeit at the cost of reduced image quality and spatial and temporal resolution (supplemental video 3). The efficiency of data acquisition may be considerably improved by using parallel imaging, which is based on undersampling of the raw data by using information from multiple receiver coils.1 The improved scan efficiency may be translated into reduced scan time or improved resolution, at the cost of some loss in signal-to-noise. Temporal resolution can also be improved by phase sharing, a …