Figure 6.

Process of determination of the duration of vortical blood flow in the main pulmonary artery A vortex of the blood flow in the main pulmonary artery is defined as being present in a cardiac phase if velocity vectors in the pulmonary artery form closed concentric ring-shaped curves that are parallel to the right ventricular outflow tract orientation, which is shown in the middle two images. The duration of the vortical blood flow in the main pulmonary artery is specified as the number of cardiac phases with vortical blood flow divided by all 20 reconstructed cardiac phases (bottom). Permission was obtained from reference number 94 (RSNA provides the permission).