Figure 1.

(a) The calcification phantom with 66 calcification clusters arranged in an 11 × 6 grid on clear film. Each cluster consisted of nine CaCO₃ crystals in a 3 × 3 pattern. The gray boxes indicate the schematic location of the 5 ROIs for the relative noise analysis of table 1. (b) The arrangement of the two wedge shaped breast-tissue-equivalent blocks (100% adipose and 100% glandular tissue) with the calcification phantom to make the wedge calcification phantom for imaging. The combination resulted in a 5 cm thick rectangular slab with continuously varying glandular ratio and fixed calcification size along the longer side and with fixed glandular ratio and varying calcification size along the shorter side.