Evaluating reproducibility and efficiency of a novel quantitative plaque analysis software using photon-counting detector CT and energy-integrating detector CT

Introduction Coronary CT angiography (CCTA) enables detailed quantitative assessment of coronary artery disease (CAD) by determining total plaque burden and detecting plaque progression, thereby holding robust prognostic value in predicting cardiovascular outcome. Purpose We aimed to evaluate the interplatform and interobserver reproducibility and time efficiency of Siemens Syngo Plaque Analysis, a novel semi-automated plaque quantification software, compared to MEDIS QAngio CT using both energy-integrating detector CT (EID-CT) and photon-counting detector CT (PCD-CT) data. Methods In total, we enrolled 170 patients in the study: 86 patients were scanned using conventional EID-CT, while 84 using a dual-source PCD-CT. Quantitative plaque analysis was carried out using dedicated plaque analysis tools: the Siemens Syngo Plaque Analysis software (Software 1) and MEDIS QAngio CT software (Software 2) by two independent readers. Lesions with a volume smaller than 10 mm³ were excluded from the study. Total plaque volume (TPV), and total measurement time spent on the analysis were recorded. Interplatform agreement for TPV measurements between the two software tools was assessed using Bland-Altman analysis for each CT scanner. Intraclass correlation coefficient (ICC) was calculated for TPV. Results Among the 550 lesions analyzed, mean TPV was 122.2 ± 148.4 mm³ using Software 1 and 92.7 ± 117.5 mm³ using Software 2 (p < 0.001). Software 1 demonstrated significantly shorter measurement times than Software 2 (3.9 ± 2.5 vs. 22.9 ± 8.8 minutes; p < 0.001) and showed excellent intra- and interobserver reproducibility for both CG and PCD-CT (ICC: 0.995–0.998), whereas reproducibility with Software 2 was lower (ICC: 0.84–0.88). PCD-CT showed improved agreement in TPV assessment, with a lower mean bias between the two software tools (15.0 vs. 45.3 for EID-CT), and a smaller absolute difference between automated and manual measurements using Software 1, compared to EID-CT (2.5±23.4 vs 6.6±28). Conclusion(s) The prototype software offers a promising approach for rapid and reproducible quantification of total plaque volume. Compared to EID-CT imaging, the application of PCD-CT technology reduces the need for manual corrections and decreases interplatform variability.