Ultrasonic coda wave analysis techniques localize defects in fields such as seismography and nondestructive testing. In medical ultrasound, these techniques might provide novel mapping of tissue properties in diseases characterized by local fibrosis. In this work, we present an approach for localizing variation in scattering properties in the diffuse regime with an array transducer in medical ultrasound. This approach estimates coda wave decorrelation as the array is displaced by 0.5 mm, allowing data acquisition at two slightly different spatial locations. An inverse problem is solved as in nondestructive testing based on coda wave decorrelation estimates and a locally-estimated diffusion constant. The developed approach is demonstrated in a tissue-mimicking phantom to assess sensitivity to variation in scattering properties. Next, the ability of the approach for localizing regions of increased multiple scattering in biological tissues is assessed with a large multiple scattering bead in an ex vivo porcine cardiac sample. Through these experiments, the ability to map variation in multiple scattering is demonstrated for the first time, with a mean localization error of 1.42 ± 3.5 mm for this low-resolution mapping technique. While the goal of this technique is to map defects in the diffuse regime rather than to develop a conventional image, contrast ratios in the resulting images were in good agreement with scattering concentrations in phantom studies: 1.98 ± 0.05 for a 2× scattering target, 1.37 ± 0.02 for a 1.4× scattering target, 0.65 ± 0.02 for a 0.7× scattering target, and 0.49 ± 0.03 for a 0.5× scattering targets.

中文翻译：

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在存在运动的情况下实现漫散射的无创映射

超声波尾波分析技术可定位地震学和无损检测等领域的缺陷。在医学超声中，这些技术可能为以局部纤维化为特征的疾病的组织特性提供新的映射。在这项工作中，我们提出了一种方法，用于在医学超声中使用阵列换能器定位漫反射区域中散射特性的变化。当阵列位移 0.5 毫米时，这种方法估计尾波去相关，允许在两个略有不同的空间位置采集数据。在基于尾波去相关估计和局部估计扩散常数的无损测试中解决了逆问题。所开发的方法在组织模拟体模中得到证明，以评估对散射特性变化的敏感性。下一个，该方法用于定位生物组织中增加的多次散射区域的能力是用离体猪心脏样本中的大多次散射珠评估的。通过这些实验，首次证明了绘制多重散射变化的能力，这种低分辨率映射技术的平均定位误差为 1.42 ± 3.5 毫米。虽然该技术的目标是绘制漫反射区域中的缺陷而不是开发传统图像，但所得图像中的对比度与体模研究中的散射浓度非常一致：2×散射目标为 1.98 ± 0.05，1.37 1.4×散射目标为±0.02，0.7×散射目标为0.65±0.02，0.5×散射目标为0.49±0.03。