Figure 4: Registration through the use of fiducial points formed by injection of dual-labeled stem cells with PET-MR contrasts into heart tissue. Image (a) is the original MR image, image (b) is the original PET image, and image (c) is the transformed PET image overlaid on top of the MR image. The arrows point to the injection sites, which were used as fiducial markers for registration using MAR-GUI.