PATIENT DISPLACEMENT ANALYSIS USING THE GENERALIZED HOUGH TRANSFORM

Introduction A major goal in electronic portal imaging is to automaticall y measure patient setup deviation between or even during treatment sessions. For several reas ons this is a very challenging task. Especially the low contrast of the portal images due to the high radiation energy and the possibility of out-of-plane rotations are limiting factor s. They require robust techniques that are able to handle a certain amount of deformation between th e images. We present a novel approach using an extended version of the Generalized Hough Transform (GHT).