Although there is an increased lifetime risk when the aortic diameter exceeds 6 cm, predicting aneurysm progression is nearly impossible and dissection and rupture also occur at diameters under 6 cm. The assessment of aortic hemodynamics and the presence of altered flow patterns, as well as distribution and changes in wall shear stress (WSS) and the oscillatory shear index (OSI), using 4D phase contrast cardiovascular magnetic resonance (CMR) may provide further insights in how aneurysms develop and in assessing the risk of dissection. The purpose of this study was to investigate in patients with dilated ascending aorta the flow patterns and vessel wall parameters in order to correlate these hemodynamics factors with changes in aorta size.