The invention provides a method for generating a non-invasive measure of blood vessel rigidity for a subject. The method includes obtaining 2D ultrasound data and 3D ultrasound data of the blood vessel from a given measurement location. The 2D ultrasound data provides information relating to a movement of the blood vessel and the 3D ultrasound data provides information relating to a shape of the blood vessel. A motion of the blood vessel is then determined based on the movement of the blood vessel. The method then includes providing the determined motion of the blood vessel, the shape of the blood vessel and an obtained non-invasive pressure measurement to a biomechanical model. A measure of rigidity is then determined based on the biomechanical model.