Photon-Counting Computed Tomography

This prospective cohort study aims to determine whether high-risk coronary plaques identified by novel Photon-Counting Detector CT (PCCT) independently predict future major adverse cardiovascular events (MACE). Participants will be followed for MACE and revascularization. The primary hypothesis is that the incidence of MACE is significantly higher in patients with PCCT-defined high-risk plaque than in those without. Additionally, patients will undergo Optical Coherence Tomography (OCT) and angiography within a month after PCCT; PCCT results will be compared with OCT in a cross-sectional analysis, and diagnostic performance will be evaluated against follow-up data.

Pulmonary embolism (PE) is a serious and potentially life-threatening condition caused by blood clots in the lungs. A particular type, subsegmental pulmonary embolism (SSPE), involves very small branches of the pulmonary arteries. Although these clots occur in smaller vessels, their risk of recurrence and complications may be similar to larger clots. Conventional CT pulmonary angiography (CTPA) is the standard imaging test for suspected PE, but image quality can sometimes be limited by motion artifacts, poor contrast filling, or body habitus, making the detection of SSPE challenging. Photon-counting computed tomography (PCCT) is a new CT technology that provides higher image resolution, lower radiation dose, and improved visualization of small blood vessels. Early studies suggest PCCT may reduce motion artifacts and increase the accuracy of detecting SSPE compared with conventional CT. This prospective cohort study will compare PCCT with dual-source CT in patients with suspected acute PE. The study aims to determine whether PCCT improves the detection rate and image quality for SSPE, and whether it can provide more reliable diagnostic information to guide clinical care.