Cardiac magnetic resonance used to compute aortic pulse wave velocity. (A) Pulse wave velocity is estimated by measuring the transit time (Δt) of the aortic wave between the sinotubular junction (STJ) and distal descending aorta (DD) sampling sites, (B) which are separated by a centreline distance (ΔL) which can be calculated using a 2D oblique-sagittal view of the aorta. (C) The transit time is estimated as the difference in arrival time of the aortic wave between both sampling sites. (D) Segmentation of the aorta in 2D phase contrast (PC) MRI acquired at a selected sampling site can provide flow and velocity profiles. (E) Arrival time at a sampling site is derived by calculating the intercept of a linear regression line fitted to the systolic upstroke in the velocity profile.