title: Deep tissue photoacoustic imaging using a miniaturized 2-D capacitive micromachined ultrasonic transducer array.
abstract: In this paper, we demonstrate 3-D photoacoustic imaging (PAI) of light absorbing objects embedded as deep as 5 cm inside strong optically scattering phantoms using a miniaturized (4 mm × 4 mm × 500 μm), 2-D capacitive micromachined ultrasonic transducer (CMUT) array of 16 × 16 elements with a center frequency of 5.5 MHz. Two-dimensional tomographic images and 3-D volumetric images of the objects placed at different depths are presented. In addition, we studied the sensitivity of CMUT-based PAI to the concentration of indocyanine green dye at 5 cm depth inside the phantom. Under optimized experimental conditions, the objects at 5 cm depth can be imaged with SNR of about 35 dB and a spatial resolution of approximately 500 μm. Results demonstrate that CMUTs with integrated front-end amplifier circuits are an attractive choice for achieving relatively high depth sensitivity for PAI.
authors.affiliation: Department of Radiology and Bio-X Program, Stanford University, Palo Alto, CA 94035, USA. ksraj@stanford.edu
authors.forename: Sri-Rajasekhar
authors.initials: SR
authors.lastname: Kothapalli
authors.forename: Te-Jen
authors.initials: TJ
authors.lastname: Ma
authors.forename: Srikant
authors.initials: S
authors.lastname: Vaithilingam
authors.forename: Omer
authors.initials: O
authors.lastname: Oralkan
authors.forename: Butrus T
authors.initials: BT
authors.lastname: Khuri-Yakub
authors.forename: Sanjiv Sam
authors.initials: SS
authors.lastname: Gambhir
mesh_terms: D000818:Animals; D002645:Chickens; D006197:Hair / Q000737:chemistry; D006736:Horses; D008904:Miniaturization; D018482:Muscle, Skeletal / Q000737:chemistry; D019047:Phantoms, Imaging; D061088:Photoacoustic Techniques / Q000295:instrumentation* / Q000379:methods*; D014159:Transducers; D014463:Ultrasonography / Q000295:instrumentation*