X-ray Aifact is -

Common aifacts (all forms of radiography) motion aifact due to patient movement resulting in a distoed image image compositing (or twin/double exposure) superimposition of two structures from different locations due to double exposure of same film/plate radiopaque objects on/external to the patient (e.g. debris in the housing debris in the housing caused by the collimator tube can cause small trapezoidal regions, indicative of lead shavings