Representative mid-ventricular short-axis images from a cine gradient echo acquisition at end diastole (left) and end systole (right). Planimetry of the epicardial (red line) and endocardial (blue line) walls for all slices spanning the left ventricle can be used to quantify end-diastolic volume, end-systolic volume, stroke volume, ejection fraction, myocardial mass, and cardiac output. In this example, the Cinetool program (GE Healthcare) was used to planimeter and compute ventricular volumes, but the analysis can be performed using other commercially available image analysis software.