Photon-counting CT with tungsten as contrast medium: Experimental evidence of vessel lumen and plaque visualization

Abstract Background and aims We aimed to investigate the potential of a preclinical photon-counting detector CT (PCT) scanner with an experimental tungsten-based contrast medium for carotid artery imaging. Methods A carotid artery specimen was imaged on a PCT system using the multi-energy bin option (pixel size 0.5 x 0.5 mm2; tube voltage 140 kVp, contrast media-dependent energy thresholds: iodine 20, 75 keV; tungsten 20, 68 keV) at two radiation doses (CTDIvol of 100 mGy and 10 mGy) with iodine and tungsten as contrast media at equal mass-concentrations. Standard CT, virtual non-calcium (VNCa) and calcium-only images were reconstructed. Subjective image quality (4-point Likert scale) was rated using histology as reference. Noise and attenuation measurements were performed. Simulations were conducted to assess the material-decomposition efficiency for different object diameters. Results Image quality on VNCa images was significantly higher for tungsten at lower dose (reader 1/reader 2: 2, [2,2]/2, [2,2] vs 1.5, [2,1]/1, [1,1.75], p Conclusions PCT employing the multi-energy bin option in combination with tungsten as contrast media enables improved carotid artery imaging with respect to lumen and plaque visualization and image noise.