Quality assurance in mammography: Artifact analysis

Evaluation of mammograms for artifacts is essential for mammographic qualit y assurance. A variety of mammographic artifacts (ie, variations in mammogr aphic density not caused by true attenuation differences) can occur and can create pseudolesions or mask true abnormalities. Many artifacts are readil y identified, whereas others present a true diagnostic challenge. Factors t hat create artifacts may be related to the processor (eg, static, dirt or e xcessive developer buildup on the rollers, excessive roller pressure, damp film, scrapes and scratches, incomplete fixing, power failure, contaminated developer), the technologist (eg, improper film handling and loading, impr oper use of the mammography unit and related equipment, positioning and dar kroom errors), the mammography unit (eg, failure of the collimation mirror to rotate, grid inhomogeneity, failure of the reciprocating grid to move, m aterial in the tube housing, compression failure, improper alignment of the compression paddle with the Bucky tray, defective compression paddle), or the patient (eg, motion, superimposed objects or substances [jewelry, body parts, clothing, hair, implanted medical devices, foreign bodies, substance s on the skin]). Familiarity with the broad range of artifacts and the meas ures required to eliminate them is vital. Careful attention to darkroom cle anliness, care in film handling, regularly scheduled processor maintenance and chemical replenishment, daily quality assurance activities, and careful attention to detail during patient positioning and mammography can reduce or eliminate most mammographic artifacts.