Factors affecting phantom scores at annual mammography facility inspections by the US Food and Drug Administration

Rationale and Objectives. The authors performed this study to evaluate the factors affecting phantom image score at the annual inspection of mammograp hy facilities. Materials and Methods. In 1997, three U.S. Food and Drug Administration (FD A)-trained inspectors performed inspections of all mammography facilities i n North Carolina. All federal and state inspection data were collected and evaluated by using linear regression analysis. Factors affecting the Americ an College of Radiology phantom scores were assessed. Results. Phantom score was affected by inspector identity, view box luminan ce, and optical density. All of these factors had a statistically significa nt effect on mass score (P < .05). Inspector identity yielded a statistical ly significant effect on speck group score, fibril score, and total score. Luminance yielded a statistically significant effect on both speck group sc ore and total score. Conclusion. Phantom scoring should be automated to allow for more consisten t interobserver scoring. In addition, radiology facilities can improve the likelihood of receiving a passing phantom score by reducing the ambient lig ht and increasing the view box luminance in the location where the images a re evaluated and the phantom is scored routinely. Radiologists should also consider increasing phantom and clinical image optical density to allow for improved phantom testing outcomes.