An X-ray imaging system including an X-ray source, an X-ray collimator, a real-time controllable 3D X-ray attenuator, a digital X-ray detector, and a system controller coupled to the X-ray radiation source, the collimator, the real-time controllable 3D X-ray attenuator, and the digital X-ray detector for controlling the real-time controllable 3D X-ray attenuator to reduce X-ray radiation dose and improve image quality. The real-time controllable 3D X-ray attenuator includes a top panel, a bottom panel, at least one sidewall joining the top panel to the bottom panel, an open area between the top panel, bottom panel, and at least one 2D pixel array coupled to at least one of the top panel and the bottom panel, the at least one 2D pixel array having a plurality of pixels of thin film electric coils and switching thin film field-effect transistors, wherein the open area is at least partially filled with a mixture of ferromagnetic material and medium X-ray attenuation material.