Conventional B-mode ultrasound imaging has difficulty in delineating homogeneous soft tissues with similar acoustic impedances, as the reflectivity depends on the acoustic impedance at the interface. As a quantitative imaging biomarker sensitive to alteration of biomechanical properties, speed-of-sound (SoS) holds promising potential for tissue and disease differentiation such as delineation of different breast tissue types with similar acoustic impedance. Compared to two-dimensional (2D) SoS images, three-dimensional (3D) volumetric SoS images achieved through a full-angle ultrasound scan can reveal more intricate morphological structures of tissues; however, they generally require a ring transducer. In this study, we introduce a 3D SoS reconstruction system that utilizes hand-held linear arrays instead. This system employs a passive reflector positioned opposite the linear arrays, serving as an echogenic reference for time-of-flight (ToF) measurements, and a high-definition camera to track the location corresponding to each group of transmit-receive data. To merge these two streams of ToF measurements and location tracking, a voxel-based reconstruction algorithm is implemented. Experimental results with gelatin phantom and ex vivo tissue have demonstrated the stability of our proposed method. Moreover, the results underscore the potential of this system as a complementary diagnostic modality, particularly in the context of diseases such as breast cancer.

中文翻译：

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基于反射镜的线性超声阵列体积声速成像验证研究

传统的 B 型超声成像难以描绘具有相似声阻抗的均匀软组织，因为反射率取决于界面处的声阻抗。作为一种对生物力学特性变化敏感的定量成像生物标志物，声速 (SoS) 在组织和疾病分化方面具有广阔的潜力，例如描绘具有相似声阻抗的不同乳腺组织类型。与二维（2D）SoS图像相比，通过全角度超声扫描获得的三维（3D）体积SoS图像可以揭示更复杂的组织形态结构；然而，它们通常需要环形传感器。在本研究中，我们介绍了一种使用手持式线性阵列的 3D SoS 重建系统。该系统采用与线性阵列相对的无源反射器，作为飞行时间 (ToF) 测量的回声参考，并采用高清摄像头来跟踪每组发射-接收数据对应的位置。为了合并这两个 ToF 测量和位置跟踪流，实施了基于体素的重建算法。明胶模型和离体组织的实验结果证明了我们提出的方法的稳定性。此外，结果强调了该系统作为补充诊断方式的潜力，特别是在乳腺癌等疾病的背景下。