F. L. Lizzi Center for Biomedical Engineering, Riverside Research Institute, 156 William Street, 9th Floor, New York, New York 10038, USA.
J Biomed Opt. 2010 Mar-Apr;15(2):021313. doi: 10.1117/1.3339977.
A 3-D optoacoustic imaging system was used to visualize thermal lesions produced in vivo using high-intensity focused ultrasound (HIFU). A 7.5-MHz, surgical, focused transducer with a radius of curvature of 35 mm and an aperture diameter of 23 mm was used to generate HIFU. A pulsed laser, which could operate at 755 nm and 1064 nm, was used to illuminate excised tissue and mice using a bifurcated fiber bundle resulting in two wide beams of light. Tomographic images were obtained while the specimens were rotated within a sphere outlined by a concave arc-shaped array of 64 piezo-composite transducers. These images were then combined to reconstruct 3-D volume images (voxel resolution 0.5 mm), which were acquired before and after HIFU exposure. In vivo optoacoustic images acquired at 1064 nm provided visualization of HIFU lesions. The lesion was indicated by a negative optoacoustic contrast. The molecular nature of such contrast may possibly be associated with reduction of the optical absorption due to reduced concentration of blood, tissue dehydration, denaturation of proteins and porphyrins, and reduction of thermoacoustic efficiency in the thermally treated tissue. These preliminary results demonstrate the potential of optoacoustic imaging to assess and monitor the progress of HIFU therapy.
使用高强度聚焦超声（HIFU）在体内产生的热损伤的三维光声成像系统。使用半径为 35mm 和孔径直径为 23mm 的 7.5MHz 手术聚焦换能器来产生 HIFU。使用脉冲激光，其可以在 755nm 和 1064nm 下运行，使用分叉光纤束来照亮切除的组织和老鼠，从而产生两个宽光束。在将标本旋转到由 64 个压电复合换能器组成的凹弧形阵列勾勒出的球体内部时，获得了断层图像。然后将这些图像组合以重建 3D 体积图像（体素分辨率为 0.5mm），这些图像在 HIFU 暴露前后获取。在 1064nm 处获得的体内光声图像提供了 HIFU 损伤的可视化。损伤由负光声对比度表示。这种对比的分子性质可能与血液浓度降低、组织脱水、蛋白质和卟啉变性以及热处理组织中热声效率降低导致的光吸收减少有关。这些初步结果表明光声成像有可能评估和监测 HIFU 治疗的进展。
