Fig. 4

Boxplots displaying the distribution of key aortic flow variables as measured with PC MRI in the ascending aorta: (a) stroke volume, (b) cardiac output, (c) peak systolic velocity, and (d) peak systolic flow. Blue indicates young controls, green indicates older controls, and red represents PH subjects. A bracket between two boxplots indicates a statistically significant (p < 0.05) difference between the two groups of measurements