Figure 1. Plan of the breast support table (not to scale) showing where the test blocks were positioned for the exposure measurements. The shaded area corresponds to the area of the support table that was covered when the rectangular test object was placed 160 mm from the chest wall edge of the support table. The positions of the test object when placed 40 mm, 80 mm and 120 mm from the chest wall edge of the support table are also indicated. When semi-circular blocks were used, the distance from the chest wall was measured to the furthest point on the semi-circle.