Pixel shift or reregistration is a post-processing technique used to improve misregistration artifact in digital subtraction angiography, where two images to be subtracted are spatially realigned with respect to one another, by shifting pixels vertically, horizontally or obliquely.
Pixel shifting may be performed manually or through the use of automated techniques.
In digital subtraction angiography, misregistration is the most common cause of image degradation, where patient motion results in a spatial misalignment between the mask and runoff images.