1. A system comprising: an interface to: receive a mask x-ray image of a patient volume; and receive a plurality of sequential x-ray images of the patient volume including a contrast medium; an image data processor to: subtract the mask x-ray image from each of the plurality of sequential x-ray images to generate a plurality of sequential x-ray difference images; filter each of the plurality of sequential x-ray difference images based on one or more filter parameters to generate a plurality of sequential filtered x-ray difference images; combine each of the plurality of sequential filtered x-ray difference images with a corresponding one of the plurality of sequential x-ray difference images based on a weight to generate a plurality of combined sequential x-ray images; filter each of the plurality of sequential x-ray difference images based on a second one or more filter parameters to generate a second plurality of sequential filtered x-ray difference images change filter parameters; and combine each of the second plurality of sequential filtered x-ray difference images with a corresponding one of the plurality of sequential x-ray difference images based on the weight to generate a second plurality of combined sequential x-ray images; and a display to display the plurality of combined sequential x-ray images sequentially, and the second plurality of combined sequential x-ray images sequentially.