Coronary CT Angiography Applications with photon-counting CT

The first photon-counting computed tomography (PCCT) was installed in Hong Kong in December 2023. I would like to discuss the background and clinical uses of quantum technology in PCCT for coronary angiography. The photon-counting detector is a new, advanced technology that uses detectors that discriminate the energy of individual photons in the x-ray beam and convert the detected individual photons into electric signals. By comparison with traditional CT (energy-integrating detector CT, EID-CT), it offers multiple advantages over standard energy-integrating detectors, including uniform photon weighting across multiple x-ray energies. 10 clinical cases of the patients were compared using PCCT and EID-CT, regarding the image quality of proximal, middle, and distal vessels, calcified plaque, stents, non-calcified plaque, and artefacts of pericardial calcification. The coronary stents and calcified plaque can be assessed by the special features of true-lumen that allow for calcium removal based on material decomposition. The ultra-high-resolution scanning protocol has advantages in demonstrating the in-stent lumen of coronary arteries. Mono-energetic images improve the diagnostic value of cardiac CT angiography. This new technology promises to overcome the blooming artefacts of heavy calcified coronary plaques or beam-hardening artefacts in patients with coronary stents. PCCT enables improved image quality and diagnostic confidence for coronary CT angiography examinations in comparison to EID-CT.