Multi-layer phase analysis: quantifying the elastic properties of soft tissues and live cells with ultra-high-frequency scanning acoustic microscopy.
Multi-layer phase analysis: quantifying the elastic properties of soft tissues and live cells with ultra-high-frequency scanning acoustic microscopy.
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DOI：
10.1109/tuffc.2012.2240
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发表时间：
2012-04
期刊：
影响因子：
--
通讯作者：
Derby B
中科院分区：
文献类型：
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作者：
Zhao X;Akhtar R;Nijenhuis N;Wilkinson SJ;Murphy L;Ballestrem C;Sherratt MJ;Watson RE;Derby B
扫描声学显微镜是表征柔软生物组织和细胞弹性特性的潜在有力工具。在本文中，我们提出了一种方法，多层相分析（MLPA），可用于提取局部声速值，既适用于玻璃载玻片上的薄组织切片，也适用于细胞培养塑料上的培养细胞，分辨率接近1 μm。该方法利用了从基片表面反射的声波与声透镜内部反射的声波之间的干涉中保留的相位信息。在实践中，一叠声图像从声焦点在衬底表面以上4 μm处开始捕获，并以0.1 μm的增量向下移动。通过调整声波频率和栅极位置等扫描参数来获得最佳相位和横向分辨率。在计算声速之前，对数据进行离线处理，以提取基材中任何倾角的相位信息。在这里，我们将这种方法应用于皮肤切片和成纤维细胞，并将我们的数据与以前用于软组织和细胞表征的V(f)（电压对频率）方法进行比较。与V(f)方法相比，MPLA方法不仅降低了信号噪声，而且可以在不对组织或细胞参数进行先验假设的情况下实现。
Scanning acoustic microscopy is potentially a powerful tool for characterising the elastic properties of soft biological tissues and cells. In this paper, we present a method, Multi-Layer Phase Analysis (MLPA), which can be used to extract local speed of sound values, for both thin tissue sections mounted on glass slides and cultured cells grown on cell culture plastic, with a resolution close to 1 μm. The method exploits the phase information that is preserved in the interference between the acoustic wave reflected from the substrate surface and internal reflections from the acoustic lens. In practice, a stack of acoustic images are captured beginning with the acoustic focal point 4 μm above the substrate surface and moving down in 0.1 μm increments. Scanning parameters, such as acoustic wave frequency and gate position, were adjusted to obtain optimal phase and lateral resolution. The data were processed offline to extract the phase information with the contribution of any inclination in the substrate removed prior to the calculation of sound speed. Here, we apply this approach to both skin sections and fibroblast cells, and compare our data with the V(f) (voltage vs frequency) method that has previously been used for characterisation of soft tissues and cells. Compared with the V(f) method, the MPLA method not only reduces signal noise but can be implemented without making a priori assumptions with regards to tissue or cell parameters.