1. A system for automatically segmenting a plurality of image frames in an anatomical scan, the system comprising: a storage device storing the image frames, wherein the image frames comprise a series of time-separated image frames taken during the anatomical scan; a user interface device allowing a user to manually segment a first image frame of the image frames in order to form a manually segmented first image frame, the manually segmented first image frame including a first contour manually created by the user for delineating an anatomical structure in the first image frame; an image processor coupled to the storage device and configured to perform a non-rigid registration between the first image frame and a second image frame of the image frames, wherein the second image frame is adjacent the first image frame in the series and the non-rigid registration involves determining a point correspondence between pixel locations in the first image frame and pixel locations in the second image frame; the image processor further configured to automatically segment the second image frame based on the non-rigid registration in order to form an automatically segmented second image frame, the automatically segmented second image frame including a second contour delineating the anatomical structure in the second image frame, wherein the second contour is automatically created by the image processor transforming prior pixel locations of the first contour on the first image frame to new pixel locations for the second contour on the second image frame according to the non-rigid registration between the first image frame and the second image frame; and the image processor further configured to iteratively segment a plurality of subsequent image frames in the series of time-separated image frames by transforming a previously automatically generated contour for an already segmented image frame to form a newly automatically generated contour for an adjacent image frame according to a non-rigid registration performed by the image processor between the already segmented image frame and the adjacent image frame; whereby the first image frame is manually segmented by the user to delineate the anatomical structure, and the second image frame and the plurality of subsequent image frames in the series of time-separated image frames are thereafter automatically segmented by the image processor to delineate the anatomical structure.