A system and method for a molecular breast imaging (MBI) are provided. One MBI system includes at least one cadmium zinc telluride (CZT) detector having a plurality of pixels and a registered parallel hole collimator coupled to a face of the CZT detector. The registered parallel hole collimator includes a plurality of collimator holes, wherein the plurality of collimator holes are aligned with the plurality of pixels, and the spatial dimensions of the plurality of holes are configured based on characteristics of the CZT detector and the registered parallel hole collimator.