Observer performance comparison of digital radiograph systems for stereotactic breast needle biopsy

RATIONALE AND OBJECTIVES: Two digital radiograph systems for stereotactic mammography, one using a lens to couple a Lanex Regular screen to a back-illuminated charge-coupled device (CCD) and one using a fiber-optic taper to couple a Min-R Regular-type screen to a front-illuminated CCD, were evaluated with respect to observer performance. METHODS: A contrast-detail phantom was imaged in a variety of equivalent exposure conditions on both systems. Six observers viewed images on a video monitor and recorded which objects were detected. RESULTS: Performance (percent correct detections) with the lens-coupled system using the Lanex Regular screen was significantly higher than with the fiber-optic-coupled system using the Min-R Regular-type screen. CONCLUSION: Differences in absorption efficiencies of phosphors used, as well as differences in design of the two cameras, can explain differences in observer detection performance.