The thesis assess the robustness of 4D flow MRI for analyzing aortic hemodynamics and valvular flow, as well as exploring the clinical potential of this technique in patients with aortic and valvular disease. The first part of the thesis evaluates the reproducibility of segmenting the aortic lumen and calculating various hemodynamic parameters, demonstrating that these processes can be performed accurately and consistently. The second part examines the natural course of aortic hemodynamics during aging, concluding that hemodynamic parameters remain relatively stable. Furthermore, different hemodynamic phenotypes are identified in patients with aortic root and ascending aortic dilatation, possibly explaining the presence of dilatation. Nederlandse Hartstichting, Universiteitsbibliotheek, Hart Onderzoek Nederland, Pie Medical Imaging, KPMG, and ChipSoftLUMC / Geneeskund