1. An apparatus for segmenting a first series of 2D or 3D images obtained from a target object within a patient, comprising: a transform calculator which calculates a series of transformations, wherein each transformation comprises an operation for defining a best fit between two images of the first series of images, the transformations including: (1) a first transformation of the series of transformations between a first image of the series and a subsequent second image of the series and (2) a second transformation between the first and a subsequent third image; a segmenter which segments the first image of the first series is generated; an image converter which applies the first transformation to the segmentation of the first image to generate a second image segmentation corresponding to the second image and applies the second transformation to the first segmentation to generate a third image segmentation corresponding to the third images, wherein the segmentation of the first series of images is applied to a second series of images.