FIGURE 3. Experimental setup. Most notable sections of apparatus have been labeled: gelatin breast phantom (A), anthropomorphic torso phantom (B), 500-mL beaker simulating bladder (C), 20-cm-diameter flood phantom simulating brain (D), 2 PEM detector units (E), x-ray tube of breast biopsy apparatus (Lorad, Danbury, CT) (F), biopsy needle positioning unit (G), biopsy gun (H), and proximal compression plate (I).