The invention relates to the adaptation of a 3D-surface model to boundaries of an anatomical structure, especially the right ventricle. A first viewing plane is defined corresponding to a default view, especially a four chamber view. A long axis is defined. Then a second, third and optionally a fourth viewing plane are represented intersecting the axis in predefined distances from the starting point and end point thereof. On the viewing planes different markers are represented, controlled and, if required, the position thereof is adapted, especially the position of the intersection points of the axis with the second and third viewing planes, as well as the position of a characteristic line, which together with the end point of the axis spans a characteristic plane of the structure. The 3D-surface model is adapted to the structure by way of the long axis and the position of the characteristic plane.