The CIRS Model 016A incorporates two 17.5 micron thick gold-nickel alloy bar patterns. (Model 019-500) These bar patterns are positioned at 90 degrees to allow assessment of resolution perpendicular and parallel to anode-cathode axis in just one exposure. The targets have 17 segments from 5 lp to 20 lp/mm and are equivalent to 25 microns of lead or 2.6 mm of aluminum at 20 keV. The patterns are permanently embedded in a thin acrylic wafer (Model 016AW) to protect them from wear or damage. The phantom body is available in BR12 or BR50/50. It enables consistent, reproducible positioning at 4.5 cm above the breast support plate and 1 cm from the chest wall, centered laterally (as recommended by the American College of Radiology). The Model 016A includes a 30x hand held microscope and handling instructions.