1. A computer-implemented method for detecting a microcalcification cluster in reconstructed volumes of a three-dimensional digital breast tomosynthesis image, comprising: receiving, at a computing device, a three-dimensional digital breast tomosynthesis image; reconstructing, at the computing device, the three-dimensional digital breast tomosynthesis image to create a reconstructed three-dimensional digital breast tomosynthesis image; enhancing, at the computing device, a microcalcification candidate in each slice of the reconstructed three-dimensional digital breast tomosynthesis image to obtain an enhanced three-dimensional digital breast tomosynthesis image by simultaneously: 1) determining a multi-scale calcification response for each voxel (x,y,z) of the microcalcification candidate, and 2) one of: a) enhancing a signal-to-noise ratio of a microcalcification in the reconstructed three-dimensional digital breast tomosynthesis image, or b) enhancing a signal intensity of the microcalcification in the reconstructed three-dimensional digital breast tomosynthesis image; wherein the multi-scale calcification response includes: a) filtering the reconstructed three-dimensional digital breast tomosynthesis image with a plurality of smoothing filters where an amount of smoothing for each smoothing filter is determined by a scale, and the plurality of filters includes a set of scales; b) finding a calcification response at each voxel of the reconstructed three-dimensional digital breast tomosynthesis image for each scale of the set of scales, where, among the set of scales, the calcification response at a central voxel of a three-dimensional microcalcification is higher when the scale is such that a shape of the smoothing filter approximately matches a shape of the three-dimensional microcalcification; and c) combining, among the set of scales, each calcification response using a non-linear operator at each voxel of the reconstructed three-dimensional digital breast tomosynthesis image; and detecting, at the computing device, potential individual microcalcifications that form a microcalcification cluster within the enhanced three-dimensional digital breast tomosynthesis image.