Scientific Computation Research Center, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY , 12120, USA.
Department of Medical Physics, University of Wisconsin, Madison, WI, 53706, USA.
Med Phys. 2017 Aug;44(8):4194-4203. doi: 10.1002/mp.12372. Epub 2017 Jul 12.
Elastography has emerged as a new tool for detecting and diagnosing many types of diseases including breast cancer. To date, most clinical applications of elastography have utilized two-dimensional strain images. The goal of this paper is to present a new quasi-static elastography technique that yields shear modulus images in three dimensions.
An automated breast volume scanner was used to acquire ultrasound images of the breast as it was gently compressed. Cross-correlation between successive images was used to determine the displacement within the tissue. The resulting displacement field was filtered of all but compressive motion through principal component analysis. This displacement field was used to infer spatial distribution of shear modulus by solving a 3D elastic inverse problem.
Three dimensional shear modulus images of benign breast lesions for two subjects were generated using the techniques described above. It was found that the lesions were visualized more clearly in images generated using the displacement data de-noised through the use of principal components.
We have presented experimental and algorithmic techniques that lead to three-dimensional imaging of shear modulus using quasi-static elastography. This work demonstrates feasibility of this approach, and lays the foundation for images of other, more informative, mechanical parameters.
弹性成像是一种新兴的工具，可用于检测和诊断包括乳腺癌在内的多种疾病。迄今为止，弹性成像的大多数临床应用都利用了二维应变图像。本文的目的是提出一种新的准静态弹性成像技术，可生成三维剪切模量图像。
使用自动乳腺容积扫描仪获取乳房在轻柔压缩时的超声图像。通过互相关来确定组织内的位移。通过主成分分析过滤除压缩运动之外的所有运动，从而对所得到的位移场进行滤波。通过求解三维弹性反问题，利用该位移场推断剪切模量的空间分布。
使用上述技术为两名受试者生成了良性乳腺病变的三维剪切模量图像。结果发现，通过使用主成分进行去噪处理后的位移数据生成的图像中，病变显示得更清晰。
我们提出了实验和算法技术，可通过准静态弹性成像实现剪切模量的三维成像。这项工作证明了该方法的可行性，并为其他更具信息量的机械参数图像奠定了基础。
