title: Computer simulation study of Siemens star x-ray image artifacts.
abstract: In the Siemens star image, exact determination of the first disappearance frequency, which is used to measure the focal spot size, is difficult since the disappearance band has a finite width and the image also has other artifacts. The origin of these artifacts and their appearance was studied by Siemens star image simulation on a digital computer. The simulated images were manipulated by using many different modulation and phase transfer functions. It is shown that the bending of spokes is not related to zero contrast; exact triplet splitting can occur only at the disappearance frequency, and therefore splitting is a valuable indicator of that frequency.
mesh_terms: D003201:Computers; D008962:Models, Theoretical; D055585:Physical Phenomena; D010825:Physics; D011859:Radiography / Q000592:standards*; D013679:Technology, Radiologic; D014965:X-Rays