Ultra-high-resolution (UHR) photon-counting coronary CT angiography demonstrated significantly higher precision than standard-resolution (SR) PCCT for quantifying coronary stenosis, particularly in heavily calcified vessels. Compared with invasive 3D quantitative coronary angiography (QCA), UHR-PCCT reduced median stenosis measurement error from 6% to 3% and achieved near-perfect agreement for CAD-RADS classification.
The study also demonstrated that the primary benefit of UHR-PCCT stems from its 0.2 mm acquisition mode, which markedly reduces calcium blooming artifacts and improves lumen visualization. While diagnostic accuracy improved substantially, these gains came at the expense of a 2.7-fold increase in radiation dose compared with standard-resolution PCCT.
Importantly, spectral calcium subtraction (Quantum PURE Lumen) did not outperform native UHR imaging, indicating that improved spatial resolution is currently more valuable than post-processing for accurate coronary lumen assessment.
