Photon-counting detector CT enables more precise assessment of coronary artery stenosis

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Hungarian Academy of Sciences. Introduction In contrast to conventional energy-integrating detectors, photon-counting detector (PCD) CT translates the photon energy directly to electric signal, which allows image acquisition with lower noise and improved spatial resolution. Objective The aim of our study was to assess coronary stenosis by comparing conventional CT and PCD-CT. Method In our retrospective study, we included patients who underwent coronary CT angiography (CCTA) performed by PCD-CT between January and December 2022. The control population consisted of consecutive patients who underwent coronary CCTA with a 280-slice CT. In our study, heart transplanted patients, patients with stent, pacemaker or valve implantation, or non-diagnostic image quality were excluded. The degree of coronary stenosis was evaluated according to the following classification: normal coronary artery (0%), minimal (1–24%), mild (25–49%), moderate (50–69%), severe stenosis (70–99%) or occluded coronary artery (100%). Results A total of 812 consecutive patients were included in our study (n=401 control, n=412 PCD-CT). There was no difference between the two groups in mean age (58.1±11.9 vs. 58.7±12.8 years) and sex (48.4% vs. 42.6% female). We found a significant difference in the degree of CAD between conventional CT and PCD-CT as follows: normal coronary arteries 29 vs 26%; minimum 23 vs 31%; mild 20 vs 23%; moderate 15 vs 10%; severe 12 vs 9%; occluded 3 vs 2%, respectively (all p<0.001). Conclusions According to our preliminary results, PCD-CT is less likely to overestimate the degree of stenosis and can detect smaller plaques more precisely.