Automatic aortic diameter and peak velocity measurements. Phase-contrast MR angiogram (MRA) data from the 4D flow sequence was calculated and used to segment the entire aorta. Panel A shows example planes placed at landmark locations, and used along the entire centerline to measure aortic diameter and peak velocity. Diameter and velocity measurements are then computed from obtained planes and normalized to standard landmarks. Panel B shows the 95% confidence interval for the aortic diameter measurements by gender and age. Panel C shows the 95% confidence interval for the peak velocity measurements by gender and age. Red points indicates significant difference (p<0.05) between groups.