Four-dimensional (4D) image are widely used to capture the respiration-induced motion of the abdominal organs in free-breathing radiotherapy. However, due to the breathing variability, appropriate assignment of images to each phase is critical in revealing the motion of anatomy structures. In this study, we proposed a novel approach to develop high-quality retrospective 4D-MRI. Instead of sorting images only based on their respiratory phases, the proposed strategy sorted the images using both the respiratory phases and the internal surrogate positions. The proposed strategy was tested using in-vivo human abdominal images.