Tissue-mimicking phantoms are widely used for the calibration, evaluation and standardisation of medical imaging systems, and for clinical training. For photoacoustic imaging, tissue-mimicking materials (TMMs) that have tuneable optical and acoustic properties, high stability, and mechanical robustness are highly desired. In this study, gel wax is introduced as a TMM that satisfies these criteria for developing photoacoustic imaging phantoms. The reduced scattering and optical absorption coefficients were independently tuned with the addition of TiO2 and oil-based inks. The frequency-dependent acoustic attenuation obeyed a power law; for native gel wax, it varied from 0.71 dB/cm at 3 MHz to 9.93 dB/cm at 12 MHz. The chosen oil-based inks, which have different optical absorption spectra in the range of 400 to 900 nm, were found to have good photostability under pulsed illumination with photoacoustic excitation light. Optically heterogeneous phantoms that comprised of inclusions with different concentrations of carbon black and coloured inks were fabricated, and multispectral photoacoustic imaging was performed with an optical parametric oscillator and a planar Fabry-Pérot sensor. We conclude that gel wax is well suited as a TMM for multispectral photoacoustic imaging.
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机译:模仿组织的模型被广泛用于医学成像系统的校准,评估和标准化,以及用于临床培训。对于光声成像,非常需要具有可调节的光学和声学特性,高稳定性和机械鲁棒性的组织模拟材料(TMM)。在这项研究中,引入凝胶蜡作为TMM,可以满足开发光声成像体模的这些标准。减少的散射和光吸收系数可通过添加TiO2和油基油墨来独立调整。随频率变化的声衰减服从幂定律。对于天然凝胶蜡,它从3 MHz时的0.71 dB / cm变化到12 MHz时的9.93 dB / cm。发现所选的油基油墨在400到900 nm范围内具有不同的光吸收光谱,在光声激发光的脉冲照明下具有良好的光稳定性。制作了由不同浓度的炭黑和彩色墨水组成的光学异构体,并使用光学参量振荡器和平面Fabry-Pérot传感器进行了多光谱光声成像。我们得出的结论是,凝胶蜡非常适合用作多光谱光声成像的TMM。
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