The ability of coherent X-ray scatter to provide the molecular structure of breast tissues could add a new dimension in X-ray breast imaging capable of tracking the molecular structural changes during disease progression and of improving the sensitivity to low-contrast lesions without increasing the radiation dose. Work is under way to build a laboratory prototype dual-sensor breast-imaging scanning system, which combines the diagnostic information from both the transmitted primary and the forward scattered X-rays. This required the design and development of a coherent X-ray scatter detection system based on a high-resistivity multielement two-dimensional (2-D) Si-pad array, a multichannel low-noise pulse processing front-end electronics chip, the XA1.3, and a new DAQ system. X-rays in the energy range of 17-45 keV can be detected with a FWHM energy resolution of 1-3 keV. Results on the characterization and optimization of the detector-readout electronics-DAQ system and its performance to measure diffraction signatures of most commonly used breast-equivalent materials of interest are presented.