There is provided a method for registration of intravital anatomical imaging modality image data and nuclear medicine image data of a patient's heart comprising: obtaining anatomical image data including a heart of a patient outputted by an anatomical intravital imaging modality； obtaining at least one nuclear medicine image data outputted by a nuclear medicine imaging modality, the nuclear medicine image data including the heart of the patient； identifying a segmentation of a network of vessels of the heart in the anatomical image data； identifying a contour of at least part of the heart in the nuclear medicine image data, the contour including at least one muscle wall border of the heart； correlating between the segmentation and the contour； registering the correlated segmentation and the correlated contour to form a registered image of the anatomical image data and the nuclear medicine image data； and providing the registered image for display.
