Method and apparatus for determining a pcd output model in a computed tomography imaging system

An apparatus for determining a model characterizing an output from a photon-counting detector (PCD) used in a computed tomography (CT) system, the PCD having a plurality of pixels, the apparatus comprising:

• processing circuitry configured to
• construct a PCD output model that has a plurality of model parameters including a first model parameter, where the first model parameter set is dependent on an incident count rate on the PCD, and dependent on a pixel position in the PCD;
• receive calibration data acquired by scanning a plurality of combinations of basis materials, under a plurality of incident count rates;
• and
• estimate the plurality of model parameters based on the received calibration data.

A non-transitory computer-readable medium storing a program that, when executed by processing circuitry, causes the processing circuitry to execute a method for determining a model characterizing an output from a photon-counting detector (PCD) used in a computed tomography (CT) system, the PCD having a plurality of pixels, the method comprising:

• constructing a PCD output model that has a plurality of model parameters including a first model parameter set, where the first model parameter set is dependent on an incident count rate on the PCD, and dependent on a pixel position in the PCD;
• receiving calibration data acquired by scanning a plurality of combinations of basis materials, under a plurality of incident count rates;
• and
• estimating the plurality of model parameters based on the received calibration data.