Imagery by magnetic resonance (IMR) represents a new modality of medical imagery based on the interaction between the magnetic fields produced by radio-frequency waves and living substance. IMR finds an interesting application in the study of different stages of myocardial infarction. In 30 cases of myocardial infarction IMR was compared with thallium tomoscintigraphy and echocardiography. In the acute stage, myomalacia appears in IMR as a superbrilliant zone, and in the chronic stage parietal thinning and dyskinesias are apparent. Intraventricular thromboses, but also hemostasis in aneurysmatic or akinetic sites are visualised as a high-intensity signal within these areas. IMR represents therefore a new means of evaluation of size and evolution of the necrosis. This procedure provides also functional informations about the contraction and flow anomalies.