Ultrasound elastography: Development of novel technologies and standardization

Abstract

Ultrasound elastography has been developed as a modality that provides novel diagnostic information on tissue stiffness and replaces conventional palpation used for breast examination. Although various techniques for ultrasound elastography have been proposed in the 1990s, it was difficult to develop a practical system for clinical use. The combined autocorrelation method of producing elasticity images with high-speed processing and accuracy was developed by our group. It achieves a wide dynamic range for strain estimation. In 2003, we developed the world's first commercialized equipment for elastography for clinical use. It was revealed that even nonexperts could achieve precise diagnosis of breast cancer on the basis of ultrasound elastography results as well as experts since the criterion on tissue elasticity is much simpler than conventional B-mode images. Nowadays, there are different types of equipment for elastograpy, then features and equipment of each method, i.e., their merits and limitations, must be clarified for their appropriate use. Recently, to help users of ultrasound elastography, academic societies of medical ultrasound, such as WFUMB, EFSUMB, and JSUM, have started to prepare guidelines on such methods. In this review, I outline the development of ultrasound elastography and the recent steps toward its standardization.

Shear wave mapping of skeletal muscle using shear wave wavefront reconstruction based on ultrasound color flow imaging

“…4) To characterize soft tissue by stiffness, several imaging methods have been proposed. [5][6][7][8][9] Strain measurement by manual compression is used to measure the tissue stiffness. [10][11][12][13] Several imaging systems are provided by adding an autocorrelation image processing function to a general-purpose ultrasonic imaging system in order to obtain strain images; however, imaging parameters are not directly related to tissue elasticity.…”

Accurate evaluation of viscoelasticity of radial artery wall during flow-mediated dilation in ultrasound measurement

“…19,20) On the other hand, for the noninvasive characterization of viscoelasticity, there have been several methods based on the hysteresis property between the force and the displacement, 21) and based on the dispersion of shear wave propagation velocity. 22) In the present study, for the measurement of viscoelasticity in the radial artery wall, changes in thickness and pressure were simultaneously measured. In our previous study, the change in thickness was measured using highfrequency ultrasound transmission with a center frequency of 22 MHz.…”

Feasibility of nondestructive testing using transient vibrations excited by acoustic radiation force

“…Various studies have been conducted on VA, [12][13][14][15][16][17][18] mainly for application to biomedical imaging, such as the detection of lesions and calcifications in soft tissues. Elastography, [19][20][21] like strain elastography and shear wave elastography, is a type of VA method. VA has also been applied to the nondestructive testing of solid materials.…”