Design of catheter for combined intravascular photoacoustic and ultrasound imaging

Intravascular photoacoustic (IVPA) imaging aims to detect and differentiate atherosclerotic plaques based on the optical absorption of the plaque constituents. From the high resolution IVPA images and the corresponding co-registered intravascular ultrasound (IVUS) images, functional and structural information about the atherosclerotic plaque can be acquired and, therefore, the vulnerability of the atherosclerotic plaque may be determined. Moreover, by using the plasmonic nanoparticles as contrast agents, IVPA images can capture the molecular and cellular signature of the atherosclerotic plaque. However, for in-vivo IVUS/IVPA imaging, an integrated catheter consisting of IVUS imaging transducer and an intravascular light delivery system is needed. In this paper, a prototype of the integrated catheter for IVUS/IVPA imaging was constructed based on a commercially available single element IVUS imaging catheter and an optical fiber. The integrated imaging catheter was tested using the tissue mimicking phantoms. The results of our study suggest that the integrated imaging catheter for in-vivo IVUS/IVPA imaging can be designed based on ultrasound probe combined with a fiber optical light delivery system.