Development of integrated OCT/US/PAT system for intravascular Imaging - PROJECT SUMMARY Coronary artery disease (CAD) is the most prevalent cardiovascular disease, impacting over 18 million adults and causing more than 350,000 deaths annually in recent years. Acute coronary events are primarily caused by ruptured atherosclerotic plaques, emphasizing the need for early detection and accurate identification of plaque types (stable versus vulnerable) as the first line of defense. Obtaining detailed morphology and functional information on atherosclerotic plaques is crucial for advancing clinical management of atherosclerosis. The objective of this proposal is to develop a single intravascular imaging system incorporating intravascular ultrasound (IVUS), photoacoustic tomography (PAT), optical coherence tomography (OCT), and polarization-sensitive OCT (PSOCT) to study and characterize plaque vulnerability. The multimodal imaging probe, requiring only a single disposable guide wire and catheter, aims to reduce costs, risks, procedure time, and radiation exposure. Building upon integrated IVUS/OCT and IVUS/PAT technology developed in our lab, the proposed OCT/US/PAT system includes significant advancements for enhanced clinical translation. It combines the high molecular sensitivity of PAT at 1720 nm, broad imaging depth of US, high spatial resolution, and extended penetration depth of 1.7-μm OCT, along with mechanical evaluation using PSOCT. The system provides physicians with a powerful clinical instrument for studying, diagnosing, and managing vulnerable plaques. The specific aims are to: 1) Design and construct a multimodal confocal OCT/US/PAT imaging probe; 2) Design and develop the OCT/US/PAT system using a 10-kHz, 1720 nm pulsed laser for PAT and a 100-kHz swept-source laser for OCT/PSOCT; 3) Demonstrate the efficacy of the proposed system via in vivo porcine model. We expect the development of the proposed OCT/US/PAT technology to bring tremendous impact to both basic science and clinical understanding of plaque pathogenesis. This will enhance the clinicians' ability to identify vulnerable lesions, tailor interventional therapy, and monitor disease progression. More importantly, it will be a powerful tool that provides a quantitative means to benchmark and evaluate new medical devices and therapies.