A comparison of four mammographic image quality test objects.

The need for rigorous image quality assurance in mammography is well documented (Pritchard Report, 1989). However, there is still debate over the suitability of those image quality test objects commercially available. We have been able to compare three contemporary test objects with the “Barts” test object which has been in use since 1980 and has been used as a standard by many workers (Kirkpatrick & Law, 1987). The four mammographic test objects have been compared using six mammographic film-screen combinations. The following test objects were used. The “Barts” mammographic image quality test object (White & Tucker, 1980). This object contains several series of opacities designed to mimic mammographic diagnostic features, some being fat equivalent, some water equivalent, some skin equivalent and some equivalent to calcifications, which are immersed in an epoxyresin scattering medium. The object is designed to assess contrast and resolution combined in various ways. The Dupont mammographic image quality t...