title: High-speed intravascular photoacoustic imaging at 1.7 μm with a KTP-based OPO.
abstract: Lipid deposition inside the arterial wall is a hallmark of plaque vulnerability. Based on overtone absorption of C-H bonds, intravascular photoacoustic (IVPA) catheter is a promising technology for quantifying the amount of lipid and its spatial distribution inside the arterial wall. Thus far, the clinical translation of IVPA technology is limited by its slow imaging speed due to lack of a high-pulse-energy high-repetition-rate laser source for lipid-specific first overtone excitation at 1.7 μm. Here, we demonstrate a potassium titanyl phosphate (KTP)-based optical parametric oscillator with output pulse energy up to 2 mJ at a wavelength of 1724 nm and with a repetition rate of 500 Hz. Using this laser and a ring-shape transducer, IVPA imaging at speed of 1 frame per sec was demonstrated. Performance of the IVPA imaging system's resolution, sensitivity, and specificity were characterized by carbon fiber and a lipid-mimicking phantom. The clinical utility of this technology was further evaluated ex vivo in an excised atherosclerotic human femoral artery with comparison to histology.
authors.affiliation: Department of Physics and Astronomy, Purdue University, West Lafayette, IN, 47906, USA ; These authors contributed equally to this work.
authors.forename: Jie
authors.initials: J
authors.lastname: Hui
authors.affiliation: Key Laboratory of Space Laser Communication and Detection Technology, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China ; University of Chinese Academy of Science, Beijing 100049, China ; These authors contributed equally to this work.
authors.forename: Qianhuan
authors.initials: Q
authors.lastname: Yu
authors.affiliation: Department of Biomedical Engineering, NIH Ultrasonic Transducer Resource Center, University of Southern California, Los Angeles, CA, 90089, USA ; These authors contributed equally to this work.
authors.forename: Teng
authors.initials: T
authors.lastname: Ma
authors.affiliation: Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, 47906, USA.
authors.forename: Pu
authors.initials: P
authors.lastname: Wang
authors.affiliation: Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, 47906, USA.
authors.forename: Yingchun
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Department of Cellular & Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Bruning
authors.affiliation: Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, 92612, USA.
authors.forename: Yueqiao
authors.initials: Y
authors.lastname: Qu
authors.affiliation: Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, 92612, USA.
authors.forename: Zhongping
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Biomedical Engineering, NIH Ultrasonic Transducer Resource Center, University of Southern California, Los Angeles, CA, 90089, USA.
authors.forename: Qifa
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: Department of Cellular & Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Sturek
authors.affiliation: Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, 47906, USA ; jcheng@purdue.edu.
authors.forename: Ji-Xin
authors.initials: JX
authors.lastname: Cheng
authors.affiliation: Key Laboratory of Space Laser Communication and Detection Technology, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China ; wbchen@mail.shcnc.ac.cn.
authors.forename: Weibiao
authors.initials: W
authors.lastname: Chen
keywords: (110.0110) Imaging systems; (110.5125) Photoacoustics; (140.3460) Lasers; (170.1610) Clinical applications; (170.5120) Photoacoustic imaging