CT Detector Calibration Coefficients for Ring Artifact Reduction

The patent applies preliminary action by performing detector calibration before the actual CT imaging process. A calibration phantom is scanned first to obtain calibration data, which is then used to generate calibration coefficients that correct detector response inconsistencies. This preliminary calibration step ensures that the main imaging process benefits from pre-compensated detector responses, significantly improving ring artifact reduction effectiveness while maintaining image quality for accurate medical diagnosis.

The patent introduces a calibration phantom as an intermediary object that mediates between the radiation detectors and the imaging process. The phantom contains known structures with specific attenuation characteristics that serve as references for calculating calibration coefficients. By using this intermediary, the system can accurately determine detector response characteristics without requiring complex direct measurements, thereby improving calibration accuracy while keeping the overall process manageable through standardized procedures.

The patent applies parameter changes by utilizing the known attenuation coefficients of specific materials in the calibration phantom (such as water, bone, or contrast agents) to create a system of equations that can be solved for calibration coefficients. By changing the approach from direct measurement to using known physical parameters of the phantom materials, the system achieves high calibration precision through mathematical modeling rather than time-consuming iterative measurements, thereby reducing calibration time while maintaining accuracy.