The patented amorphous selenium (a-Se) BrillianSe X-ray detector is designed for high-brilliance imaging. The hybrid a-Se/CMOS detector uses an a-Se photoconductor with high intrinsic spatial resolution for direct conversion of X-ray photons to electric charge. The electronic signal is then read out by a low noise CMOS active pixel sensor (APS). Without the need to first convert X-ray photons to visible light, as in indirect scintillator-based approaches, thinning of the conversion layer to minimize optical scatter is not necessary. BrillianSe™ provides a unique combination of high spatial resolution using 8 μm pixels, and high Detective Quantum Efficiency (DQE) for energies up to 110 keV. This combination enables efficient imaging at low flux and high energy, as well as propagation-based (grating less) in-line phase-contrast enhancement for improved sensitivity when imaging low-density materials.