Institut Langevin, ESPCI Paris, PSL Research University, CNRS UMR7587, INSERM U979, Paris 6 University and Paris 7 University, 17, Rue Moreau, 75012 Paris, France.
Phys Med Biol. 2018 Jul 25;63(15):155005. doi: 10.1088/1361-6560/aacfaf.
We present herein 3D elastic tensor imaging (3D ETI), an ultrasound-based volumetric imaging technique to provide quantitative volumetric mapping of tissue elastic properties in weakly elastic anistropic media. The technique relies on (1) 4D ultrafast shear wave elastography (SWE) at very high volume rate (e.g. > 8000 Hz, depending only on the imaging depth), (2) a volumetric estimation of shear wave velocity using the eikonal equation and (3) a generalized 3D elastic tensor-based approach. 3D ETI was first evaluated using numerical simulations in homogeneous isotropic and transverse isotropic media. Results showed that 3D ETI can accurately assess tissue stiffness and tissue anisotropy in weakly transversely isotropic media (elastic fractional anisotropy coefficient < 0.34). Experimental feasibility was shown in vitro in a transverse isotropic phantom. Quantification of the elastic properties by 3D ETI was in good agreement with 2D SWE results performed at different orientations using a clinical ultrafast ultrasound scanner. 3D ETI has the potential to provide a volumetric quantitative map of tissue elastic properties in weakly transversely isotropic soft tissues within less than 20 ms of acquisition for the entire imaged volume.
我们在此提出三维弹性张量成像（3D ETI），这是一种基于超声的容积成像技术，可提供弱各向异性弹性介质中组织弹性特性的定量容积映射。该技术依赖于 (1) 非常高的体积率（例如 > 8000 Hz，仅取决于成像深度）的 4D 超快速剪切波弹性成像 (SWE)，(2) 利用 eikonal 方程对剪切波速度进行容积估计，以及 (3) 广义的基于 3D 弹性张量的方法。3D ETI 首先在均匀各向同性和横向各向同性介质的数值模拟中进行了评估。结果表明，3D ETI 可以准确评估弱横向各向异性介质中的组织刚度和组织各向异性（弹性各向异性系数 < 0.34）。在横向各向同性的体模中进行了实验可行性研究。通过 3D ETI 对弹性特性的定量分析与使用临床超快速超声扫描仪在不同方向上进行的 2D SWE 结果吻合良好。3D ETI 有可能在不到 20 ms 的采集时间内，为整个成像体积提供弱横向各向异性软组织的组织弹性特性的容积定量图谱。
