Improved tool for testing screen-film contact in mammography

Good screen-film contact is essential to obtain high definition in radiographic images. We compared the conventional test tool for measuring screen-film contact, which uses #8 mesh (eight wires per inch [about three wires per centimeter]), with a prototype tool of #40 copper mesh. The conventional tool did not adequately test screen-film contact for mammography, in which significantly higher resolution is obtained. We believe #40 copper mesh should be used to test screen-film contact of mammographic cassettes. We also found that entrapped air may reduce screen-film contact and, therefore, recommend that cassettes be loaded at least 15 minutes before they are exposed.