Until now, mouse respiratory movement has never been deeply studied and the data acquired during breathing period are not used to obtain 4D cardiac images in mice. First, this study aims at evaluating the respiration movement and its impact on the heart region. First, motion field maps of the thorax during breathing demonstrated motion of 1mm in the anteroposterior direction. Second, 4D cardiac images were reconstructed using the data acquired during the breathing periods and a technic based on sliding window. This improvement allows a considerable acquisition time shortening (about 30%) for 3D cine whole heart imaging on small animals.