CT Perfusion

Coronary artery disease (CAD) is the leading cause of mortality and morbidity worldwide. Coronary Computed Tomography angiography (CCTA) gained a pivotal clinical role for excellent sensitivity in rule-out CAD, but has limited specificity for a tendency to overestimate stenoses and for the lack of information about their hemodynamic impact. Fractional Flow Reserve derived from CT (FFR-CT) and stress CT perfusion (CTP) have been recently proposed to complement CCTA in the non-invasive assessment of myocardial ischemia, increasing the specificity and avoiding unnecessary catheterization. However, on energy-integrating (EID)-CT, FFR-CT has suboptimal performance, while CTP is affected by high radiation exposure. Both these approaches may benefit by the introduction of the new Photon Counting Detector (PCD)-CT technology, but data completely lacks. Aim of the study is to assess the performance of PCD-CT in the identification of significant CAD combining CCTA with FFR-CT and spectral CTP.

Peripheral artery disease (PAD) affects millions worldwide and can lead to serious complications such as leg ulcers, gangrene, and amputation. Current imaging methods mainly evaluate large blood vessels but do not measure microcirculation in the foot. Computed tomography perfusion (CTP) is a new technique that can assess blood flow in small vessels. The purpose of this study is to see whether combining CTP measurements with standard CT angiography images and patient clinical information can help predict which PAD patients are more likely to have poor outcomes after surgery to restore blood flow (revascularization). Poor outcomes include death or major limb problems such as amputation or need for another procedure. This is an observational study. Researchers will collect data from about 200 adult PAD patients who are scheduled to undergo revascularization. Participants will receive routine care including CT scans before and after surgery. No experimental drugs or devices are given. Researchers will follow participants for up to 2 years after surgery through medical records and phone calls to track their recovery and any complications. The results may help doctors identify high-risk patients earlier and improve treatment decisions.