1. A method of creating a model of a target organ of a patient using a processor, the method comprising: receiving at least two three-dimensional (3D) medical images of the target organ, the at least two 3D medical images comprising respective shape models; generating a deformation matrix between the at least two shape models of the target organ based on the at least two corresponding 3D images of the target organ; extracting constraints about the target organ from a two-dimensional (2D) image of the target organ; and preparing the model of the target organ based on the constraints and the deformation matrix for display on a display device, wherein the generating comprises: selecting a reference shape model from the at least two shape models; and calculating the deformation matrix based on a deformation relationship between the reference shape model and a remaining shape model of the at least two shape models.