An x-ray-based cased wellbore tubing and casing imaging tool is disclosed, the tool including at least a shield to define the output form of the produced x-rays; a two-dimensional per-pixel collimated imaging detector array; a parallel hole collimator format in one direction that is formed as a pinhole in another direction; Sonde-dependent electronics; and a plurality of tool logic electronics and PSUs. A method of using an x-ray-based cased wellbore tubing and casing imaging tool is also disclosed, the method including at least: producing x-rays in a shaped output; measuring the intensity of backscatter x-rays returning from materials surrounding a wellbore; determining an inner and an outer diameter of tubing or casing from the backscatter x-rays; and converting image data from said detectors into consolidated images of the tubing or casing.