Figure 1

Breast tissue equivalent phantom positioning, detector field of view, and regions of interest. This shows the large field of view (largest rectangle) for the Hologic Selenia unit, the phantom (gray rectangle) placement on the detector (18 cm × 24 cm or approximately 2500 × 3400 pixels), and the regions of interest (ROIs) used for the analysis outlined with narrow light borders. The size of the large ROI is 2000 × 2500 pixels, and the size of the small ROI is 1000 × 1250 pixels.