title: High-speed and high-SNR photoacoustic microscopy based on a galvanometer mirror in non-conducting liquid.
abstract: Optical-resolution photoacoustic microscopy (OR-PAM), a promising microscopic imaging technique with high ultrasound resolution and superior optical sensitivity, can provide anatomical, functional, and molecular information at scales ranging from the microvasculature to single red blood cells. In particular, real-time OR-PAM imaging with a high signal-to-noise ratio (SNR) is a prerequisite for widespread use in preclinical and clinical applications. Although several technical approaches have been pursued to simultaneously improve the imaging speed and SNR of OR-PAM, they are bulky, complex, not sensitive, and/or not actually real-time. In this paper, we demonstrate a simple and novel OR-PAM technique which is based on a typical galvanometer immersed in non-conducting liquid. Using an opto-ultrasound combiner, this OR-PAM system achieves a high SNR and fast imaging speed. It takes only 2 seconds to acquire a volumetric image with a wide field of view (FOV) of 4 × 8 mm2along the X and Y axes, respectively. The measured lateral and axial resolutions are 6.0 and 37.7 μm, respectively. Finally, as a demonstration of the system's capability, we successfully imaged the microvasculature in a mouse ear in vivo. Our new method will contribute substantially to the popularization and commercialization of OR-PAM in various preclinical and clinical applications.
authors.affiliation: Future IT Innovation Laboratory, Department of Creative IT Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk, 37673 Republic of Korea.
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Future IT Innovation Laboratory, Department of Creative IT Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk, 37673 Republic of Korea.
authors.forename: Changho
authors.initials: C
authors.lastname: Lee
authors.affiliation: School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk, 37673 Republic of Korea.
authors.forename: Kyungjin
authors.initials: K
authors.lastname: Park
authors.affiliation: Oz-tec Co., Ltd., Rm 901, IT convergence industrial bldg., 47, Gyeongdaero 17 gil, Bukgu, Daegu, 41566 Republic of Korea.
authors.forename: Sangyeob
authors.initials: S
authors.lastname: Han
authors.affiliation: Future IT Innovation Laboratory, Department of Creative IT Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk, 37673 Republic of Korea.
authors.forename: Chulhong
authors.initials: C
authors.lastname: Kim