Clinical performance evaluation of the prototype digital breast tomosynthesis system

The rapid development and clinical use of digital mammography in the past decade has made possible the development of digital breast tomosynthesis (DBT), which can overcome the limitation of conventional mammography and improve the specificity of mammography with improved marginal visibility of lesion and early breast cancer detection, especially for women with dense breast. The purpose of this study is to characterize the physical properties of DBT system and to optimize the exposure condition using effective modulation transfer function (eMTF), effective noise power spectrum (eNPS), and effective detective quantum efficiency (eDQE). The first generation KERI prototype digital tomosyntesis system for breast imaging using CMOS flat panel detector was used in this study. It was found that the spatial frequency dependent metrics depend on both the inherent properties of the detector and imaging geometry including breast thickness. For thicker breast, eDQE decreases as scatter fraction increases at fixed tube voltage. Moreover, eMTF shows no significant difference as changing tube voltage while eDQE at 27 kVp is relatively degraded. Consequently, the quantitative evaluation of the DBT system with different exposure condition and breast thickness should be fully considered before building the system and application in clinical hospital.