Fig. 1. MR axial images of a northern elephant seal pup during cardiac phase-contrast data acquisition. Localizer image (A) shows the location selected for flow analysis and the position of the aorta. In phase-contrast images A and B, image intensity is proportional to the velocity component of the blood along the superior/inferior direction. Image B was obtained during systole (frame 4 of 36), and image C is near the end of diastole (frame 27 of 36). Black indicates superior (cranial) flow and white represents flow in the inferior (caudal) direction.