Exposure artifacts in raster scanned equalization radiography.
The image artifacts characteristic of a scanning chest radiographic system are reviewed. The technique employs a pulsed beam of radiation swept in an overlapping raster pattern that can result in severe ripple and scan line artifacts with improper scanning parameters. A one-dimensional treatment of the scanner geometry shows that the artifacts can be eliminated when the beam width is an integral multiple of interpulse spacing. An extension to a two-dimensional analysis indicates that with the collimator geometries employed, artifact-free images are not possible with a fixed x-ray frequency but can be achieved when a variable frequency source is used. A treatment of the sensitivity for artifact formation shows that with proper choice of scanning parameters sizable errors in beam width can be tolerated without significant artifact formation.
D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D055585:Physical Phenomena; D010825:Physics; D011856:Radiographic Image Enhancement / Q000295:instrumentation* / Q000379:methods; D012542:Scattering, Radiation