Abstract
Recently, some computer aided diagnoses (CAD) systems has been introduced until now. Temporal subtraction technique, as one of the CAD systems, can emphasize temporal changes of interested regions by subtracting a previous image from a current one, which are images of a same patient. A previous image is deformed to suit a current image considering a variation of pose and inhalation differences when a patient accepts CT inspection at different times and subtracted from a current image. However, accurate registration is difficult because organizations such as a vessel are distributed three-dimensionally in a lung region. It is caused that each shift vector (shift amount and direction of a pixel) is less consistency to surrounding shift vectors in some area of a lung region by mis-registration and many artifacts are remained on temporal images. In this paper, we propose a method of registration based on GGVF considering information of structures in a lung regions and smoothing of shift vectors, and aim to improve registration and reduce artifacts in a subtraction image.
