title: Deep reflection-mode photoacoustic imaging of biological tissue.
abstract: A reflection-mode photoacoustic (PA) imaging system was designed and built to image deep structures in biological tissues. We chose near-infrared laser pulses of 804-nm wavelength for PA excitation to achieve deep penetration. To minimize unwanted surface signals, we adopted dark-field ring-shaped illumination. This imaging system employing a 5-MHz spherically focused ultrasonic transducer provides penetration up to 38 mm in chicken breast tissue. At the 19-mm depth, the axial resolution is 144 microm and the transverse resolution is 560 microm. Internal organs of small animals were imaged clearly.
authors.affiliation: Washington University in St. Louis, Department of Biomedical Engineering, Optical Imaging Laboratory, Campus Box 1097, One Brookings Drive, St. Louis, Missouri 63130-4899, USA.
authors.forename: Kwang Hyun
authors.initials: KH
authors.lastname: Song
authors.forename: Lihong V
authors.initials: LV
authors.lastname: Wang
mesh_terms: D000162:Acoustics / Q000295:instrumentation; D000818:Animals; D002645:Chickens; D003952:Diagnostic Imaging / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007834:Lasers; D055095:Optics and Photonics / Q000295:instrumentation; D009928:Organ Specificity; D051381:Rats