Comparison of TSVD, MTSVD, and Tikhonov unfolding methods for reconstruction of X-ray spectra

Abstract

Unfolding X-ray spectrum is a powerful tool for quality control of X-ray tubes. Generally, the acquisition of the X-ray spectrum in diagnostic radiology departments is complicated and difficult due to high photon flux, and pulse pile up. Therefore, indirect methods, including Compton scattering, or flat panel-wedge techniques, are usually used to determine the X-ray spectrum in diagnostic energy range. The X-ray spectrum could be unfolded using radiation absorbing, or scattering materials, and proper detectors. In this study, three models were simulated using MCNP5 code, a) Compton scattering b) flat panel-wedge, c) CR-wedge. The primary spectrum was reconstructed using Tikhonov, TSVD, and MTSVD unfolding techniques. The results of this study indicate that the X-ray spectra for 40, and 50 kVp can be unfolded with good accuracy using the above methods. The unfolding accuracy of Tikhonov method was found to be better than the TSVD, and MTSVD methods.