This invention relates to computed tomographic (CT) imaging, and more particularly to methods and apparatus for measuring a spectral content and a total energy of an x-ray beam after attenuation by an object.
At least one known CT imaging system detector measures a current signal that is a representative of an energy of the x-ray beam received by the detector cells but does not measure both an energy of an x-ray beam and a spectral content of the x-ray beam after being attenuated by a patient.