Maximum likelihood resolution recovery in X-ray CT with an extended focal spot

This paper presents a method for recovering resolution in X-ray computed tomographic (CT) systems where the projection of an extended focal spot onto the detector results in significant blur. This system blur is shift-variant and depends on the exact geometry of the CT system and the shape of the focal spot. The responses for the likelihood-based reconstructions show improved resolution over traditional FBP; however, the resolution properties are space-variant and anisotropic in both cases.