Phantom. A cylindrical 6-liter phantom with 10 test tubes and a 10 x 100 mm metal rod in its center was made [1]. Tubes were filled with an aqueous solution of K₂HPO₄ at concentrations of 10, 50, 100, 200, and 300 mg/cm³ to imitate a whole range of X-ray density of human tissues. Stainless steel, copper, and aluminum rods were used.

Study. The study was conducted on a Siemens Somatom CT in Dual Energy (DE) mode (100 kV, 250 mA and 140 kV, 483 mA) with and without Metal Artifact Reduction (MAR) post-processing, pitch 0.5, slice thickness 1 mm, without metal and with each of rods located along the axis of the phantom.

Data-processing. To assess the quality of images, the authors measured the mean value and the standard deviation (SD) of signal in the test tubes, which showed the ability to accurately determine the X-ray density of the objects and the noise, respectively. The areas of interest, in this case, were allocated in such a way as to cover the maximum area without affecting the boundaries of the test tubes, to avoid the influence of edge effects. For a more stable assessment, the data (mean, SD) were averaged over the length of the tube.

In addition, a visual assessment of the artifact suppression algorithm results was performed.