A 41-year-old man with a bicuspid aortic valve (BAV) and coarctation of the aorta, as visualized by 2D phase contrast cardiovascular magnetic resonance imaging (CMR) ( Figure 1D , Supplementary data online, Videos S1 ) and contrast enhanced MR angiography ( Figure 1A ), was referred for evaluation by time-resolved 3D phase contrast (4D flow) CMR to assess the flow velocity through the coarctation and provide aortic flow characterization. Findings of the comprehensive examination demonstrate the complex haemodynamic patterns that emerge throughout the aorta secondary …