Patients with a suspected myocardial infarction are subdivided into ST-elevation and non-ST-elevation myocardial infarctions (STEMI and NSTEMI, respectively) using an ECG. While patients with STEMI are urgently referred to a cath lab, patients with NSTEMI usually undergo a planned invasive coronary angiography (ICA) anywhere from 24-72 hours after arriving to the hospital. When an invasive coronary angiography can not explain the cause of a myocardial infarction, an MRI of the heart (a CMR) is often done as a follow-up investigation. A growing body of evidence suggests that performing a CMR before the planned ICA can provide an accurate diagnosis and defer the need for an ICA in many of these patients with NSTEMI.