Validity of Using Accreditation Phantom in Quality Control of Digital Tomosynthesis

Aim: This study was undertaken to compare the two image-quality phantoms commonly used in full-field digital mammography (FFDM) and digital breast tomosynthesis (DBT) imaging. Methods: Mammography units with two targets and three filters resulting in three possible target/filter combinations and two kVp values which are widely used (28 and 32) were used for the comparison. The automatic exposure control system was used in combination with the selected kVp. The CIRS 15 mammographic accreditation phantom (MAP) and CIRS 20 (BR3D) breast imaging phantom were used with the three target/filter combinations and two kVp values. A total of 24 images were acquired and evaluated. Image score was determined as the smallest sized object detectable. The data were analyzed by using Mann-Whitney test. Results: There were significant (p<0.001) differences between the detectability of fibers present in the two phantoms, but there were no differences in the detectability of specks. Conclusion: The finding in FFDM and DBT showed there were significant differences between the two phantoms (p<0.02) in fibers and specks visibility. The CIRS 20 phantom provided greater visibility of smaller structures, while the MAP was more suitable for assessing image quality of both FFDM and DBT imaging systems.