Beam hardening-respecting flat field correction of digital X-ray detectors

[paper]

The inter-pixel sensitivity variations in the X-ray at panel detector give rise to gain non-uniformity. These artifacts degrade the quality of digital radiography and uoroscopy imaging. The human anatomy attenuates the beam intensity and alters the spectrum spatially. The state-of-the-art gain correction methods are analyzed and found to be inadequate in dealing with the non-uniformity related to beam hardening. We propose a beam hardening-respecting (BHR) gain correction method. Based on a general nonlinear signal model, it relates the underlying true signal and spoiled observation, and incorporates beam quality-specific variables, including the tube voltage and human anatomy filtration. This method has demonstrated a great improvement over other commonly adopted techniques for digital X-ray at panel gain correction.