1. A graphical user interface for gating an image scan, the interface comprising: a display device; a first screen portion on the display device that displays at least one of a plurality of selected slice images of the image scan; a second screen portion on the display device that displays at least a portion of a patient's ECG signal that was obtained during the image scan; and a third screen portion on the display device that displays at least one of a coronal and sagittal projection image of the plurality of selected slices, scaled so as to appear with their correct aspect ratios.