A method and apparatus for determining a degree of deflection in a breast compression plate. The mammography apparatus further includes an optical measuring device. The method and apparatus involve (a) providing a pattern on the breast compression plate, the pattern being imagable by the optical measuring device, and having a plurality of local pattern indicia; (b) adjusting the breast compression plate to a selected height; (c) imaging the breast compression plate using the optical measuring device to provide an image of the pattern, the image having a plurality of local image indicia including an associated local image indicia for each local pattern indicia in the plurality of local pattern indicia; and (d) for each local pattern indicia in the plurality of local pattern indicia, determining an associated local deflection of the breast compression plate from the associated local image indicia.