The CIRS Model 016B incorporates a 17.5 micron thick gold-nickel alloy bar pattern. Each bar pattern is positioned at 90 degrees to allow assessment of resolution perpendicular and parallel to anode-cathode axis in just one exposure! The 016B high resolution target has 18 segments from 5 lp to 28 lp/mm. The target is equivalent to 25 microns of lead or 2.6 mm of aluminum at 20 keV. The bar pattern is permanently embedded in a thin acrylic wafer to protect it from wear or damage. The phantom body is available in BR12 or BR50/50. It enables consistent, reproducible positioning of the bar pattern 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 016B includes a 30x hand held microscope and handling instructions.