Physiological correct modelling of blood flow through the human ascending aorta is done by combining computational fluid dynamics (CFD) and magnetic resonance imaging (MRI). This method provides a relatively new approach in the analysis and quantification of the haemodynamic variables. Velocity patterns and wall shear stress distributions occurring in the ascending aorta of an individual subject are examined. Geometrical data and inflow velocity profiles just downstream of the valve were acquired from MRI measurements. Based on the extraction of arterial cross-sections a computer model of the time-dependent geometrical vessel wall was generated. After surface creation the arterial lumen was filled with an appropriate 3D finite element mesh. The mathematical description of the blood flow uses the Navier-Stokes equations applying an Arbitrary Lagrangian-Eulerian modification with respect to the time-varying geometry with externally imposed boundary motion. The numerical approach uses our recently developed finite element solver. The computational results agree very well with the measured data.