Enhancement and associative restoration of electronic portal images in radiotherapy

The Electronic Portal Imaging Device (EPID) uses a high-energy treatment beam to project the body interior of a patient on to a fluorescent screen that is scanned by a camera. Because of the imaging physics, the unprocessed images are very poor in quality. This paper presents an approach that combines an associative restoration algorithm with a fuzzy image enhancement technique. By fusing the electronic portal image with a pre-treatment captured simulator image, a higher image quality than by conventional techniques is achieved.