Early cardiac magnetic resonance imaging (CMR) scans were of inferior quality. A sig- ni cant improvement in image quality was achieved a er introducing the segmented acquisition of the k-space synchronized with patient’s ECG, performed either in breath hold or free breathing. CMR is now used widely in the clinical setting for assessment of cardiac chamber volumes, global and regional cardiac contraction, morphology and tissue charac- terization. In ammatory or post- myocardial infarction changes involve sequences which can appreciate myocardial edema or the use of late post-gadolinium contrast enhancement (LGE) to visualise di use or focal scar. Other applications include the assessment of valvular stenosis or regurgitation by means of ow me- asurement through a de ned ori ce and rst pass myocardial perfusion to assess ischemia. Last but not least, CMR is increasingly used for the assessment of congenital heart diseases, in which CMR o ers objective and directly com- parable measures during serial examinations, without any radiation exposure.