Photon-Counting Computed Tomography for Coronary Stent Imaging: In Vitro Evaluation of 28 Coronary Stents. Issue 10 (October 2021)

• Record Type: Journal Article
• Authors: Petritsch, Bernhard; Petri, Nils; Weng, Andreas M.; Petersilka, Martin; Allmendinger, Thomas; Bley, Thorsten A.; Gassenmaier, Tobias
• Is Part Of: Investigative radiology. Volume 56:Issue 10(2021)
• Publication Date: 2021-10
• Subjects: photon-counting -- detector -- computed tomography -- coronary artery stents -- cardiac; Diagnosis, Radioscopic -- Periodicals; Radiology, Medical -- Periodicals; 616.0757
• DOI: 10.1097/RLI.0000000000000787
• Languages: English
• ISSNs: 0020-9996

Abstract

Abstract : Objectives: The aim of this study was to assess in-stent lumen visibility and quantitative image characteristics of different coronary stents using a novel photon-counting detector (PCD) computed tomography (CT) system in comparison to a state-of-the-art energy-integrating detector (EID) CT scanner. Materials and Methods: In this in vitro phantom study, 28 different coronary stents ranging from 2.25 to 4.5 mm lumen diameter were expanded into plastic tubes filled with contrast agent. Stent-containing plastic tubes were positioned in a custom-made emulsion-filled phantom, which was inserted into an anthropomorphic phantom simulating a medium-sized patient. Computed tomography scans were acquired parallel to the scanners' z axis using a novel cadmium telluride–based PCD CT system (SOMATOM CountPlus; Siemens Healthcare GmbH, Forchheim Germany), operating in 2 different modes (standard-resolution mode [SR] and ultra-high-resolution [UHR] mode), and a latest generation dual-source EID CT system (SOMATOM Force; Siemens Healthcare GmbH, Forchheim). CTDIvol -matched images were reconstructed with comparable convolution kernels and using the same reconstruction parameters. In-stent lumen visibility (in %), increase in in-stent attenuation (expressed as Δ in-stent CT attenuation), and image noise (in Hounsfield unit) were manually measured. Parts of the image analysis (in-stent lumen visibility) were additionally performed in an automated way. Differences were tested using Wilcoxon signed rank test. Results: The best in-stent lumen visibility was achieved with the PCD-UHR mode and the lowest noise levels with the PCD-SR mode. The median in-stent lumen visibility was significantly higher ( P < 0.001) with PCD (SR, 66.7%; interquartile range [IQR], 63.3–72.3; UHR, 68.9%; IQR, 64.4–74.4) compared with EID (65.4%; IQR, 62.2–70.4). The Δ in-stent CT attenuation was significantly lower for PCD in both SR (78 HU; IQR, 46–108; P = 0.024) and UHR (85 HU; IQR, 59–113; P = 0.006) compared with EID (108 HU; IQR, 85–126). Image noise was significantly lower ( P < 0.001) for PCD-SR (21 HU; IQR, 21–21) compared with EID images (25 HU; IQR, 24–25.0). Conclusions: The PCD provides superior in-stent lumen visibility and quantitative image characteristics when compared with conventional EID. Abstract : Supplemental digital content is available in the text.