Photon counting detector CT can identify mild coronary artery in-stent restenosis more reliably

Abstract

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Cardiovascular Imaging Research Group, Medical Imaging Centre, Semmelweis University. Introduction The improved spatial resolution of photon-counting detector CT (PCD-CT) allows better image quality and less artefacts even in high-density structures, such as coronary artery stents. Purpose Our aim was to compare the prevalence of coronary artery in-stent restenosis using conventional CT and PCD-CT. Methods Our retrospective study included consecutive patients with coronary artery stents who underwent coronary CT angiography (CCTA) either with PCD-CT between January and December 2022 or with a 280-slice conventional CT scanner in 2019. The following categories were used: none, not severe, severe in-stent restenosis and stents with non-diagnostic image quality. Results Altogether 253 patients were included in our study (215 patients who underwent CCTA with a conventional CT and 38 patients who had PCD-CT examination). The mean age was 62.7±10.8 years and 46.8% were women. In-stent restenosis was detected significantly more frequently in case of PCD-CT examination, as compared to conventional CCTA (47.7% and 27.4%, respectively; p = 0.023). Among the 15 patients who underwent ultra-high resolution PCD-CT examination, only one (6.7%) had a non-diagnostic image quality for the assessment of in-stent restenosis, while 34 cases (15.8%) were non-diagnostic in the conventional CCTA group. Conclusions The better image quality provided by PCD-CT notably helps the evaluation of in-stent restenosis and can therefore contribute to the identification of mild in-stent restenosis. Moreover, the number of non-diagnostic CCTA scans can be decreased by using ultra-high resolution technique.