The use of cardiac magnetic resonance (CMR) has emerged in the last decades. Technical innovations provide fast and high-quality imaging sequences and CMR is often proposed as a gold-standard for the in vivo evaluation of cardiac function, morphologic details and infarct size. Also the 31-phosphorous magnetic resonance spectroscopy (MRS) is a unique tool to investigate the human myocardial high-energy phosphate (HEP) metabolism in vivo. PCr/b-ATP ratio examined by MRS is mainly used as an index for cardiac energy metabolism. We have described decreased PCr/b-ATP ratios in patients with diabetes mellitus, hypercholesterolemia and hemochromatosis. The use of CMR to study the effects of ischemia time on the evolution of myocardial infarct characteristics after an acute myocardial infarction (AMI) treated with a primary angioplasty (p-PTCA) is a promising new application of this technique. Results of this study will further help to clarify the impact of ischemia time on myocardial regional functional recovery after p-PTCA.