Findings in patient 1, 13 years after operative repair of aortic coarctation. A: contrast enhanced MRA with a tubular shaped transverse arch (white arrow tip) and an aneurysm of the proximal descending aorta with a diameter of 4.2 cm. B-D: 3D visualization of blood flow measurements using time-integrated particle traces. Note three obvious findings. In C (lateral view) blood flow acceleration and a slow vortical flow through the aneurysm with the centre of the flow vortex at the lateral wall (*) can be appreciated. B (anterior view) and D (posterior view) show pronounced helical flow in the ascending aorta (AAo, feathered arrow) and circular downstream flow in the descending aorta (DAo, open white arrows). A more detailed depiction of the temporal evolution of 3D blood flow is provided in the additional file 1.