A method of obtaining an X-ray image of a region of interest (ROI) of a target object, the method including: obtaining a first image of the target object； providing a plurality of selectable imaging modes for reimaging the target object； and obtaining a second image of the target object according to a selected imaging mode of said plurality of imaging modes； wherein said providing of a plurality of selectable imaging modes is performed such that a selection of an imaging mode can be made after obtaining said first image and before obtaining said second image.
