1. A method of reconstructing a model of an object in medical imaging, the method comprising the steps of: marking a point of at least one object of interest from at least two projection images as a seed point, where said point locates inside the object of interest in the corresponding projection image, and adding plurality of elementary object elements around the marked seed point in each direction until a criteria is fulfilled in said direction in order to reconstruct the model of the object of projection data, where priori information relating to the object of interest is connected with said elementary object element.