Ultrasound-modulated optical tomography of absorbing objects buried in dense tissue-simulating turbid media.
Ultrasound-modulated optical tomography of absorbing objects buried in dense tissue-simulating turbid media.
复制标题
埋在致密组织模拟浑浊介质中的吸收物体的超声调制光学断层扫描。
作者：
Lihong V. Wang;Xuemei Zhao
利用散射激光的连续波超声调制技术对埋藏在模拟组织浑浊介质中的物体进行成像。埋地物体的吸收系数大于背景浑浊介质。聚焦在浑浊介质中的超声波调制了通过超声波场的激光。由光电倍增管采集的调制激光反映了超声调制区域的局部力学和光学特性。通过扫描和检测超声调制光信号的变化，对埋在5 cm厚致密浑浊介质中间平面的物体进行毫米级分辨率成像。致密浑浊介质的光学特性包括0.1 cm（-1）的吸收系数和10 cm（-1）的降低散射系数，在可见光和近红外范围内与生物组织相当。研究了超声调制光信号与探测器离轴距离和探测器面积的关系。
Continuous-wave ultrasonic modulation of scattered laser light was used to image objects buried in tissue-simulating turbid media. The buried object had an absorption coefficient greater than the background turbid medium. The ultrasonic wave that was focused into the turbid media modulated the laser light that passed through the ultrasonic field. The modulated laser light that was collected by a photomultiplier tube reflected the local mechanical and optical properties in the zone of ultrasonic modulation. Objects buried in the middle plane of 5-cm-thick dense turbid media were imaged with millimeter resolution through the scanning and detecting alterations of the ultrasound-modulated optical signal. The optical properties of the dense turbid media included an absorption coefficient of 0.1 cm(-1) and a reduced scattering coefficient of 10 cm(-1) and were comparable with those of biological tissues in the visible and near-IR ranges. The dependence of the ultrasound-modulated optical signal on the off-axis distance of the detector from the optic axis and the area of the detector was studied as well.