title: Combined photoacoustic and ultrasound biomicroscopy.
abstract: We report on the development of an imaging system capable of combined ultrasound and photoacoustic imaging based on a fast-scanning single-element 25-MHz ultrasound transducer and a unique light-delivery system. The system is capable of 20 ultrasound frames per second and slower photoacoustic frame rates limited by laser pulse-repetition rates. Laser and ultrasound pulses are interlaced for co-registration of photoacoustic and ultrasound images. In vivo imaging of a human finger permits ultrasonic visualization of vessel structures and speckle changes indicative of blood flow, while overlaid photoacoustic images highlight some small vessels that are not clear from the ultrasound scan. Photoacoustic images provide optical absorption contrast co-registered in the structural and blood-flow context of ultrasound with high-spatial resolution and may prove important for clinical diagnostics and basic science of the microvasculature.
authors.affiliation: Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Tyler
authors.initials: T
authors.lastname: Harrison
authors.forename: Janaka C
authors.initials: JC
authors.lastname: Ranasinghesagara
authors.forename: Huihong
authors.initials: H
authors.lastname: Lu
authors.forename: Kory
authors.initials: K
authors.lastname: Mathewson
authors.forename: Andrew
authors.initials: A
authors.lastname: Walsh
authors.forename: Roger J
authors.initials: RJ
authors.lastname: Zemp
mesh_terms: D000162:Acoustics; D002244:Carbon / Q000737:chemistry; D003952:Diagnostic Imaging / Q000379:methods*; D004867:Equipment Design; D005385:Fingers / Q000098:blood supply / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008027:Light; D008833:Microcirculation; D008853:Microscopy / Q000379:methods*; D008855:Microscopy, Electron, Scanning / Q000379:methods; D055095:Optics and Photonics; D009991:Oscillometry / Q000379:methods; D014465:Ultrasonics; D014463:Ultrasonography
chemical_list: D002244:Carbon