Abstract
Photon-counting computed tomography (PCCT) directly detects individual X-ray photons and records their energy using semiconductor detectors. It enables high-spatial-resolution and spectral imaging, with potential advantages in heavily calcified coronary arteries and small stents. This article describes the technical principles and current evidence for coronary stenosis, stents, plaque, coronary physiology, myocardial tissue, structural heart procedures, and peripheral vessels. The strongest evidence supports improvements in image quality and diagnostic assessment; evidence for patient outcomes, radiation or contrast reduction, and cost-effectiveness remains limited. Clinical use should be tailored to the diagnostic task and supported by standardized acquisition and reconstruction protocols.
