Certain embodiments of the present invention provide a system, method and computer instructions for x-ray imaging. In an embodiment, such a system includes: an x-ray emission module configured to emit a stream of x-rays; a rotatable x-ray definition module configured to define the size and shape of the x-ray stream, wherein rotating the x-ray definition module rotates the shape of the x-ray stream; an x-ray detection module configured to detect the x-ray stream and create an image based on the detected x-rays; and an output module configured to output the image. In certain embodiments, the x-ray definition module may be configured to change the size of the x-ray stream when the x-ray definition module is rotated, for example. In certain embodiments, the x-ray detection module may be configured to rotate the image and/or change the size of the image before the image is output by the output module, for example.