Analysis of indirect method for estimation of X-ray spectrum

Reconstructing the X-ray spectrum is crucial for radiodiagnostic applications. The indirect method, based on the Archer & Wagner model, provides an approach to estimating X-ray spectra, but its accuracy and limitations require further investigation.

This study aims to evaluate the effectiveness of the Archer & Wagner model in reconstructing Xray spectra by evaluating its performance with experimental data and simulations. Furthermore, the study examines the impact of a filtering technique introduced in a subsequent work by Archer & Wagner.

The method was analyzed using experimental data and SpekPy simulations, alongside the generation of over 20,000 transmission curves and corresponding spectra from the Archer & Wagner model. Additionally, we assessed how Archer and Wagner's (1989) 0-3 g cm⁻² truncation and renormalization filter influences the accuracy of the indirectly estimated spectral parameters.

Findings indicate that, despite the model's strong ability to represent X-ray spectra, minimizing the discrepancy between transmission curves is not the most effective approach for parameter estimation. Additionally, the accuracy of X-ray parameters, such as the half-value layer and homogeneity coefficient, is closely linked to the quality of the reconstructed spectra. While the filtering technique enhances estimation, defining a standard cutoff remains a challenge.

The Archer & Wagner model effectively represents X-ray spectra, but the optimization approach based on transmission curve minimization may not be the best for parameter estimation. The quality of reconstructed spectra directly influences key X-ray parameters, and further refinement of filtering techniques is needed to establish a reliable standard cut-off.