A system and method for delivering a self-expanding stent graft within a segment of a body vessel having a branch vessel extending therefrom. Detector system 18 may include pairs of first and second detector arrays 50 and 52, with each array containing detector elements of a different design. Therefore, the high-frequency components are restored in a pseudo manner. The processing unit is configured to process the morphological images to obtain sparse motion information of the object, to use the sparse motion information and a motion model for obtaining estimated motion information about the object, and to generate a motion-corrected nuclear image based on the estimated motion information and the acquired nuclear image.