The present invention relates to an apparatus for determining a parameter of a moving object, wherein the apparatus comprises an adaptive model providing unit (12) for providing an adaptive model of the object. The user can define the region of the adaptive model by a user interface (13). The apparatus further comprises an image data set providing unit (14) for providing a spatially and temporally dependent image data set of the moving object and an adaptation unit (15) for adapting at least a defined region of the adaptive model to the spatially and temporally dependent image data set for determining a spatially and temporally dependence of the defined region. The parameter of the moving object is determined depending on the spatially and temporally dependence of the defined region by a parameter determining unit (16).
