Real-Time Intravascular Photoacoustic/Ultrasound/Optical Coherence Tomography Imaging of Pulsing Vessels Ex Vivo With and Without "Blood" Flushing.

Atherosclerotic plaque rupture causes acute cardiovascular events, necessitating accurate vulnerable plaque identification by capturing comprehensive structural and functional features, which requires novel intravascular multi-modality imaging technologies. Currently, the application of the technologies is mainly limited by moderate speed. In this study, we developed a real-time IVPA/IVUS/OCT tri-modality system by overcoming synchronization challenges and suppressing electromagnetic interference via hardware/software improvements. Ex vivo pulsing vessels imaging was performed to obtain the comprehensive information without motion artifacts. Furthermore, the alive intravascular blood environment was simulated by flowing intralipid (comparable scattering factor with blood) inside the ex vivo vessels. Benefitted from the improved imaging speed, PA and OCT signal changes of the vessels were smoothly recorded throughout manual flushing and analyzed quantitatively. To the best of our knowledge, it's the first real-time intravascular tri-modality imaging system, enabling dynamic flushing observation and providing the possibility for systematic analysis of the signal levels and distributions.