The Optimal Energy Level of Virtual Monochromatic Images From Spectral CT for Reducing Beam-Hardening Artifacts Due to Contrast Media in the Thorax

OBJECTIVE. The purpose of this study is to determine the optimal energy level of virtual monochromatic images from spectral CT compared with conventional polychromatic images for reducing beam-hardening artifacts caused by contrast media in the thorax. MATERIALS AND METHODS. A total of 101 consecutive patients who underwent chest CT with contrast enhancement were retrospectively included in this study. The same contrast media and injection protocols were applied to the whole study population. Virtual monochromatic image datasets ranging from 70 to 200 keV and conventional polychromatic images were obtained. Readers' subjective image quality scores were recorded for conventional polychromatic and virtual monochromatic images obtained at 70, 100, 130, and 200 keV. Image noise, CT attenuation difference, contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR) were also obtained in each algorithm. Comparisons of parameters between algorithms were performed. RESULTS. The best subjective image quality sc...