Cariovascular Magnetic Resonance (CMR), sometimes know as cardiac MRI is a medical imaging technology for the non-invasive assessment of the function and structure of the cardiovascular system. It is derived from and based on the same basic principles as Magnetic Resonance Imaging MRI but with optimisation for use in the cardiovascular system. These optimisations are principally in the use of ECG gating and rapid imaging techniques or sequences. By combining a variety of such techniques into protocols, key functional and morphological features of the cardiovascular system can be assessed.