An x-ray-based casing imaging tool, defined by a combination of source collimators, located cylindrically around an X-ray source and a rotatable two-dimensional per-pixel collimated imaging detector array, is provided, the tool including at least an x-ray source; a radiation shield to define the output form of produced x-rays; a direction controllable two-dimensional per-pixel collimated imaging detector array; an imaging window within the tool housing that reduces attenuation of x-rays passing through said tool housing; sonde-dependent electronics; and a plurality of tool logic electronics and PSUs. A method of using an x-ray-based casing imaging tool to determine the integrity of well casing or tubing is also provided, the method including at least: producing x-rays in a shaped output; measuring the intensity of backscatter x-rays returning from materials surrounding the wellbore; controlling two-dimensional per-pixel collimated imaging detector arrays; and converting image data from said detectors into consolidated images of the wellbore materials.