2022 journal article

Visualization of Human Skeletal Muscle Mechanical Anisotropy by Using Dual-Direction Shear Wave Imaging

IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING, 69(9), 2745–2754.

By: G. Xu*, P. Chen*, X. Jiang n & C. Huang*

co-author countries: Taiwan, Province of China 🇹🇼 United States of America 🇺🇸
author keywords: Muscles; Imaging; Transducers; Elasticity; Biomedical measurement; Anisotropic magnetoresistance; Elastography; Muscle anisotropy; skeletal muscle; shear wave elasticity imaging (SWEI); tissue elasticity; tissue isotropy
MeSH headings : Anisotropy; Elasticity; Elasticity Imaging Techniques / methods; Humans; Muscle, Skeletal / diagnostic imaging; Muscle, Skeletal / physiology; Phantoms, Imaging
Source: Web Of Science
Added: September 6, 2022

<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Objective:</i> Ultrasound (US) shear wave elasticity imaging (SWEI) is a mature technique for diagnosing the elasticity of isotropic tissues. However, the elasticity of anisotropic tissues, such as muscle and tendon, cannot be diagnosed correctly using SWEI because the shear wave velocity (SWV) varies with tissue fiber orientations. Recently, SWEI has been studied for measuring the anisotropic properties of muscles by rotating the transducer; however, this is difficult for clinical practice. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Methods:</i> In this study, a novel dual-direction shear wave imaging (DDSWI) technique was proposed for visualizing the mechanical anisotropy of muscles without rotation. Longitudinal and transverse shear waves were created by a specially designed external vibrator and supersonic pushing beam, respectively; the SWVs were then tracked using ultrafast US imaging. Subsequently, the SWV maps of two directions were obtained at the same scanning cross section, and the mechanical anisotropy was represented as the ratio between them at each pixel. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Results:</i> The performance of DDSWI was verified using a standard phantom, and human experiments were performed on the gastrocnemius and biceps brachii. Experimental results of phantom revealed DDSWI exhibited a high precision of <0.81% and a low bias of <3.88% in SWV measurements. The distribution of anisotropic properties in muscle was visualized with the anisotropic ratios of 1.54 and 2.27 for the gastrocnemius and biceps brachii, respectively. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Conclusion:</i> The results highlight the potential of this novel anisotropic imaging in clinical applications because the conditions of musculoskeletal fiber orientation can be easily and accurately evaluated in real time by DDSWI.