Photon-Counting Computed Tomography in Coronary Imaging: A Scoping Review of Current Evidence

Photon-counting computed tomography (PCCT) represents an emerging imaging technology with potential advantages for coronary artery assessment. This scoping review aimed to characterize the current body of literature on PCCT for coronary imaging and to identify existing gaps and future research priorities. A systematic scoping review was conducted in accordance with the Arksey and O’Malley framework and PRISMA guidelines. Peer-reviewed studies published in English since 2012 were retrieved from multiple electronic databases using predefined keyword combinations. Study selection and data extraction were independently performed by multiple reviewers, with discrepancies resolved through consensus. Thirty-one studies met the inclusion criteria. Of these, 40% involved human subjects, encompassing a total of 747 participants. Early investigations conducted between 2017 and 2021 were predominantly preclinical, whereas studies published from 2022 onward demonstrated a clear transition toward clinical application. Most clinical studies focused on coronary artery disease assessment (73.1%), followed by coronary stent evaluation (15.4%), or both (11.5%). Sample sizes in clinical studies were relatively small, ranging from 3 to 197 participants (median 61.8), and primarily included patients with known or suspected coronary artery disease. The majority of publications originated from the United States and Europe, often involving multinational collaborations, while data from other regions remained limited. Most studies compared PCCT with conventional computed tomography, with few direct comparisons to alternative imaging modalities such as magnetic resonance imaging. Overall, the literature reflects a maturing field transitioning from technical validation to early clinical implementation. However, limitations including small sample sizes, restricted patient diversity, geographic concentration, and limited multimodality comparisons persist. Addressing these gaps through large-scale, multicenter studies, standardized methodologies, and broader international collaboration will be essential to fully define the clinical role of PCCT in coronary imaging.