Background: Coronary computed tomography angiography (CCTA) provides non-invasive quantitative assessment of plaque burden and composition. A prerequisite for the quantitative assessment of plaque components, however, is the use of analysis programs, which provide reproducible semi-automatic plaque detection, analysis, and quantification. Commercially available plaque analysis software programs, however, may highly differ in the degree of automation of the analysis steps and their reproducibility, thus influencing the resultant imaging findings, whereas the time-spent for analysis may impact their potential for implementation into the clinical realm.
Aim: To compare the reproducibility and time-spent of two plaque analysis program tools using different automated algorithms for the quantitative assessment of coronary plaque volumes and composition in two independent patient cohorts.
Methods: The study population included 100 patients from two different cohorts, 50 patients from a single-centre (Siemens, Somatom Force (DSCT 3G)) and another 50 patients from a multi-center study (5 different >64 slice CT scanner types). Quantitative measurements of total calcified and non-calcified plaque volume of RCA, LAD and LCX were performed on a total of 300 coronaries by two independent users, using two plaque analysis programs (Tool 1: Siemens, syngo.via Frontier Coronary Plaque Analysis and Tool 2: Siemens, CT-guided PCI). In addition, the total time spent for analysis was measured with both programs.
Results: Patients in cohort 1 were 62.8 ± 10.2 years old, 10 (20.0%) were female and 4 (8.0%) had diabetes mellitus. Variabilities for the manual and the automated plaque analysis tool were 22.8%, 22.0%, 26.0% versus 2.3%, 3.9% and 2.5% between different observers and 19.7%, 21.4%, 22.1% versus 0.2%, 0.1% and 0.3% between the same observer, respectively for total, noncalcified, and calcified lesions, (p<0.001 for all between tool 1&2). Patients in cohort 2 were 70.9 ± 11.7 years old, 35 (70.0%) were female and 7 (14.0%) had diabetes mellitus. Inter- and intraobserver variability using the automated plaque analysis tool remained low at 2.9%, 2.7%, 3.0% and 3.8%, 3.7% and 4.0%, respectively for total, non-calcified and calcified lesions, for this cohort. Tool #1 required higher median time spent of 459.5(IQR=348.0-627.0) sec versus 208.5(IQR=198.0-216.0) sec per dataset compared to tool #2 (p<0.001)
Conclusion: The CT-guided PCI tool with a higher degree of automatic support and less need for manual editing for plaque analysis exhibited higher reproducibility within a lower time spent for the quantitative analysis of plaque volumes and composition. The results were assessed in a representative single-center cohort and were then verified in a multi-center & multi-vendor patient cohort.
