Method, apparatus and medical imaging system for segmenting image of object from image of organ

A method to segment an object image included in an organ in an organ image according to an embodiment of the present invention comprises the following steps of: generating a reference model of an object using prior knowledge about the object included in an organ; obtaining a first image of the organ of a subject; determining the presence of a first area where the shape of the first object cannot be estimated in the obtained first image; and segmenting a second image of the object from the first image when the first area does not exist, and segmenting the second image from the first image by estimating the traveling direction of the first area from the reference model when the first area exists.