A first gate data representing a first plurality of time gates for a first medical imaging modality (e.g., PET or CT) is provided. The first plurality of time gates are based on a plurality of cycles of an acquired physiological signal of a person. A gate width is determined for a second medical imaging modality (e.g., CT or PET). A second gate data is generated, representing a second plurality of time gates for the second medical imaging modality. Each time gate in the second plurality of time gates has the determined gate width and is generated dependent on a respective time gate in the first plurality of time gates.
