Coronary plaque quantification on energy-integrating and photon-counting detector CT: reproducibility and power modeling for mixed-platform trials
摘要
To evaluate the reproducibility of quantitative plaque characterization between energy-integrating detector (EID)-CT and photon-counting detector (PCD)-CT, identify reconstruction settings yielding the lowest variability, and model sample-size requirements for trial planning.
Materials and methodsPatients who underwent coronary CT angiography on dual-source EID-CT and PCD-CT within 30 days were screened retrospectively. EID-CT data were reconstructed using quantitative (Qr40) and vascular (Bv40) kernels, while PCD-CT data were reconstructed with Bv36/40/44 and Qr36/40/44 kernels and quantum iterative reconstruction strengths 2–4. For each plaque component (total, low-attenuation, fibrotic, and calcified), volumes were computed using fixed and adaptive Hounsfield-unit thresholds using an automated deep-learning–based plaque-quantification platform and spatially co-registered. Inter-scanner standard deviation (SD) was calculated, and optimal reconstruction pairs were used for power modeling.
ResultsThirty-eight patients (age 68.0 [64.0–72.5] years, 30 men) and 77 vessels were included. Inter-scanner correlations were very strong for total (r = 0.85–0.95), fibrotic (r = 0.74–0.94), and calcified plaque (r = 0.92–0.98), and strong for low-attenuation plaque volumes (r = 0.71–0.85). Mean bias ranged from 8.2 to 164.4 mm³ for total plaque volume. Applying the optimal reconstruction pair (Qr40EID-CT vs. Bv36PCD-CT), inter-scanner SDs were 0.14 (vessel-based) and 0.12 (patient-based). At 80% power and α = 0.05, the estimated sample sizes to detect 5% and 10% changes in total plaque volume were 116 and 29 vessels or 92 and 23 patients per group.
ConclusionQuantitative coronary plaque volumes demonstrated high inter-scanner consistency between EID-CT and PCD-CT under optimized conditions. The dual-level power-modeling framework translates inter-scanner variability into actionable sample-size estimates for study design.
Key Points