Cardiovascular imaging provides an abundant source of detailed, quantitative data on heart structure and function. Common investigations include ultrasound, computed tomography, radionuclide imaging and MRI. Many research studies have employed MRI because it is noninvasive, well tolerated and safe (no ionizing radiation), has the ability to modulate contrast, and can provide high-quality functional information in any plane and direction (Fig. 1).

Cine MRI short- (top) and long-axis (bottom) images, at end-diastole (end of ventricular filling, left), and end-systole (end of ejection, right). Contours show inner (green) and outer (blue) boundaries of the left ventricle, and the position of the mitral valve (red).

The tomographic nature of MRI data lends itself to 3D atlas building techniques and to date, all CAP imaging data has come from MRI. These studies typically consist of 6–12 cine acquisitions in the short axis orientation, with 20–50 frames through the cardiac cycle and 1–2 mm pixel resolution. Imaging protocols include gradient recalled echo (GRE) (Boxerman et al., 1998 (link)) and steady state free precession (SSFP) (Thiele et al., 2001 (link)) techniques. Studies have also contributed core laboratory analyses of the image data, in the form of annotations and contouring (Fig. 1) of the left ventricular boundaries at end-diastole (end of filling) and end-systole (end of ejection), and de-identified text data containing the clinical status and demographics of the participants.