Computerized evaluation of mammographic image quality using phantom images.

A simple, quick and computerized method for quantitatively evaluating the image quality of mammography phantom images has been developed. Images of the American College of Radiology (ACR) mammographic accreditation phantoms were acquired under different X-ray techniques, scored and ranked subjectively by five expert readers, and digitized for quantitative analysis. The contrast and signal-to-noise (contrast-to-noise) ratios of the main nodule and microcalcification group were obtained accurately and reproducibly using an image processing protocol. The contrast values were successful at discriminating differences in image quality due to variations in scatter conditions (as a result of different kVp's, and the presence or absence of an acrylic scatterer and/or a moving Bucky grid). They were more precise, reproducible and sensitive than the ACR score. In particular, the contrast of the main nodule was highly correlated (r(s) = 0.988: p<0.001) with the ranking of image quality by our panel of expert readers.