Cardiac magnetic resonance imaging (CMR – Cardiac MRI): Cardiac magnetic resonance imaging (CMR – Cardiac MRI) uses special software in magnetic resonance imaging equipment, optimized for imaging the heart which moves at a fast rate than most other structures which are stationary or moves slowly. Imaging of the heart is usually done with ECG gating so that images can be timed to contractions and relaxation of the heart. Rapid sequence imaging is required to capture the heart which contracts and relaxes at 60-100 beats per minute in a normal individual. Three dimensional reconstructions and cine imaging can be done using CMR techniques. Scars in the heart muscle (after a heart attack) can be identified by injection of gadolinium based contrast material into the veins. Normal heart muscle appear as dark and scars appear as white as they take up gadolinium.