Simultaneous correction of limited-angular-range and beam-hardening artifacts in dual-energy CT

Abstract

Dual-energy CT (DECT) with limited-angular-range (LAR) data is of interest, as it could potentially reduce radiation dose and scanning time and avoid collision of the moving gantry with the imaged subject. In DECT with LAR data, images suffer from LAR and beam-hardening (BH) artifacts. In this work, we investigate the simultaneous correction of LAR and BH artifacts for DECT with LAR data. Under a scanning configuration with overlapping arcs of low- and high-kVp spectra, data are generated from a digital suitcase phantom. A data-domain decomposition method is used to correct for the BH artifacts first, while basis images are reconstructed from the decomposed basis sinograms of LAR by use of the previously developed directional-total-variation (DTV) algorithm to correct for the LAR artifacts. Visual inspection of the monochromatic images and quantitative analysis of estimated atomic numbers suggest that the simultaneous correction of BH and LAR artifacts in DECT can effectively reduce, and almost eliminate, BH and LAR artifacts in monochromatic images from data of LAR as low as 30◦ , and also yield accurately estimated atomic numbers that are almost numerically identical to the reference values from the full-angular-range data of 360° .