Mapping 3D Strains with Ultrasound Speckle Tracking: Method Validation and Initial Results in Porcine Scleral Inflation.
Mapping 3D Strains with Ultrasound Speckle Tracking: Method Validation and Initial Results in Porcine Scleral Inflation.
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DOI：
10.1007/s10439-015-1506-1
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发表时间：
2016-07
影响因子：
3.8
通讯作者：
Liu J
中科院分区：
文献类型：
--
作者：
Cruz Perez B;Pavlatos E;Morris HJ;Chen H;Pan X;Hart RT;Liu J
本研究旨在开发和验证一种高频超声方法，用于测量眼内压升高期间巩膜中的分布3D应变。实现了一种基于互相关的三维散斑跟踪算法，计算每个跟踪点的三维位移矢量和应变张量。模拟超声射频数据从巩膜样结构在未成形和变形状态与已知的应变被用来评估的准确性和信噪比（SNR）的应变估计。建立了一个实验性的高频超声（55 MHz）系统，以获取从15到17，然后19 mmHg充气的猪眼的3D扫描。仿真证实了良好的应变估计精度和SNR（例如，轴向应变的误差小于4.5%，对于0.005至0.05的应变，SNR大于16.5）。猪眼的实验数据显示，在膨胀过程中，后巩膜的拉伸、压缩和剪切应变增加，体积比接近1，表明接近不可压缩性。本研究确立了使用高频超声散斑跟踪测量三维组织应变的可行性及其表征后眼生理变形的潜力。
This study aimed to develop and validate a high frequency ultrasound method for measuring distributive, 3D strains in the sclera during elevations of intraocular pressure. A 3D cross-correlation based speckle-tracking algorithm was implemented to compute the 3D displacement vector and strain tensor at each tracking point. Simulated ultrasound radiofrequency data from a sclera-like structure at unde-formed and deformed states with known strains were used to evaluate the accuracy and signal-to-noise ratio (SNR) of strain estimation. An experimental high frequency ultrasound (55 MHz) system was built to acquire 3D scans of porcine eyes inflated from 15 to 17 and then 19 mmHg. Simulations confirmed good strain estimation accuracy and SNR (e.g., the axial strains had less than 4.5% error with SNRs greater than 16.5 for strains from 0.005 to 0.05). Experimental data in porcine eyes showed increasing tensile, compressive, and shear strains in the posterior sclera during inflation, with a volume ratio close to one suggesting near-incompressibility. This study established the feasibility of using high frequency ultrasound speckle tracking for measuring 3D tissue strains and its potential to characterize physiological deformations in the posterior eye.