Department of Radiology and Bio-X Program, Stanford University, Palo Alto, CA 94035, USA.
IEEE Trans Biomed Eng. 2012 May;59(5):1199-204. doi: 10.1109/TBME.2012.2183593. Epub 2012 Jan 11.
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.
本文演示了使用微型(4mm×4mm×500μm)、二维电容式微机械超声换能器(CMUT)阵列(16×16 个元件,中心频率为 5.5MHz)对深度达 5cm 的强光学散射体内部的吸光物体进行三维光声成像(PAI)。本文呈现了放置在不同深度的物体的二维层析图像和三维体积图像。此外,我们研究了 CMUT 基 PAI 对在体模内 5cm 深度处吲哚菁绿染料浓度的灵敏度。在优化的实验条件下,深度为 5cm 的物体可以用约 35dB 的 SNR 和大约 500μm 的空间分辨率进行成像。结果表明,集成前端放大器电路的 CMUT 是实现 PAI 相对高深度灵敏度的一种有吸引力的选择。