Photon-counting detector CT in cardiovascular imaging: technical advances, clinical applications, and future...

This review comprehensively reviews the technical advances, cardiovascular clinical applications, current limitations, and future perspectives of photon-counting detector CT (PCD-CT) to provide evidence-based guidance for clinical imagers and researchers. A structured literature search was conducted in PubMed, Web of Science, and Embase (January 2015 to March 2025) using the terms 'photon-counting detector CT', 'cardiovascular imaging', 'coronary artery disease', 'spectral CT', and 'congenital heart disease', combined with Boolean operators. Eligible peer-reviewed original studies and authoritative technical reports published in English were screened independently by two reviewers and included by consensus. As a narrative review, no formal risk-of-bias scoring or quantitative meta-analysis was performed. PCD-CT achieves an in-plane spatial resolution of approximately 125 μm (versus ~ 208 μm for EID-CT) and reduces radiation dose by 30-54%. In a 68-patient prospective study of heavily calcified high-risk patients, ultra-high-resolution (UHR) PCD-CT angiography demonstrated a per-vessel sensitivity of 96% and a negative predictive value of 97%, and in a separate cohort 100% sensitivity with 100% negative predictive value for coronary stent patency (44 stents in 18 patients). Myocardial extracellular volume derived from PCD-CT correlates strongly with cardiac MRI (r = 0.82-0.91). In congenital heart disease, PCD-CT reduces radiation dose by more than 40% while improving diagnostic image quality from 77% to 97%. Contrast medium volume reductions of 25% or more are validated across aortic and pediatric indications. PCD-CT offers substantial technical advances across cardiovascular imaging. Large-scale, multicenter, prospective trials are needed to establish patient-level outcome benefits and support guideline integration.