title: A 3-D high-frequency array based 16 channel photoacoustic microscopy system for in vivo micro-vascular imaging.
abstract: This paper discusses the design of a novel photoacoustic microscopy imaging system with promise for studying the structure of tissue microvasculature for applications in visualizing angiogenesis. A new 16 channel analog and digital high-frequency array based photoacoustic microscopy system (PAM) was developed using an Nd:YLF pumped tunable dye laser, a 30 MHz piezo composite linear array transducer, and a custom multichannel receiver electronics system. Using offline delay and sum beamforming and beamsteering, phantom images were obtained from a 6 mum carbon fiber in water at a depth of 8 mm. The measured -6 dB lateral and axial spatial resolution of the system was 100+/-5 microm and 45+/-5 microm, respectively. The dynamic focusing capability of the system was demonstrated by imaging a composite carbon fiber matrix through a 12.5 mm imaging depth. Next, 2-D in vivo images were formed of vessels around 100 mum in diameter in the human hand. Three-dimensional in vivo images were also formed of micro-vessels 3 mm below the surface of the skin in two Sprague Dawley rats.
authors.affiliation: University of Southern California, Los Angeles, CA 90089, USA. rbitton@stanford.edu
authors.forename: Rachel
authors.initials: R
authors.lastname: Bitton
authors.forename: Roger
authors.initials: R
authors.lastname: Zemp
authors.forename: Jesse
authors.initials: J
authors.lastname: Yen
authors.forename: Lihong V
authors.initials: LV
authors.lastname: Wang
authors.forename: K Kirk
authors.initials: KK
authors.lastname: Shung
mesh_terms: D000465:Algorithms; D000818:Animals; D006225:Hand / Q000098:blood supply; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D033401:Microscopy, Acoustic / Q000295:instrumentation / Q000379:methods*; D055806:Microvessels / Q000033:anatomy & histology*; D019047:Phantoms, Imaging; D051381:Rats; D017207:Rats, Sprague-Dawley; D012867:Skin / Q000098:blood supply