Quantitative Estimation of Passive Elastic Properties of Individual Skeletal Muscle in Vivo Using Normalized Elastic Modulus-Length Curve
Quantitative Estimation of Passive Elastic Properties of Individual Skeletal Muscle in Vivo Using Normalized Elastic Modulus-Length Curve
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DOI：
10.1109/tbme.2020.2985724
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发表时间：
2020-04
影响因子：
4.6
通讯作者：
Yang Xiao;Congzhi Wang;Yang Sun;Xiangnan Zhang;L. Cui;Jinhua Yu;Hairong Zheng
中科院分区：
文献类型：
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作者：
Yang Xiao;Congzhi Wang;Yang Sun;Xiangnan Zhang;L. Cui;Jinhua Yu;Hairong Zheng
精确表征人体骨骼肌的被动弹性特性可以为功能评估和医学诊断提供有价值的信息。利用基于分段指数模型的归一化弹性模量-长度曲线，建立了一种非侵入性超声（US）方法，用于估计人体腓肠肌（GM）的被动弹性系数k、松弛长度l0和松弛弹性模量G 0，以量化GM的被动弹性特性，并将不同结果与健康和萎缩受试者相关联。应用等速测力计对32例正常人和18例萎缩性踝关节炎患者的右侧GM肌进行动态B型超声和剪切波弹性成像（SWE）检查。在踝关节旋转引起的肌肉被动拉伸过程中，通过使用Hough变换和主动轮廓法自动跟踪B型成像帧中的远端肌肉-肌腱连接位置来测量连续的肌肉长度。使用SWE成像帧获得相应的弹性模量。采用高斯-牛顿算法从归一化弹性模量-长度曲线中估计参数k、l0和G 0。在体实验结果表明，测量的肌肉弹性模量-长度数据拟合良好，所提出的模型的三个估计参数为所有受试者（0.942 < R2 < 0.997）。萎缩组的被动弹性系数k显著高于正常组（105.5 ± 45.3比48.4 ± 16.0，p < 0.001）。建议的参数允许进一步表征肌肉的基本力学性能，并有可能成为肌肉疾病诊断的有效指标。
Precise characterization of the passive elastic properties of human skeletal muscle could provide valuable information for functional assessment and medical diagnosis. Using normalized elastic modulus-length curve based on a piecewise exponential model, a non-invasive ultrasonography (US) method was developed for estimating three physiologically meaningful parameters, termed as passive-elastic coefficient k, slack length l0 and slack elastic modulus G0, to quantify the passive elastic properties of human gastrocnemius (GM) muscle, and correlate different findings with healthy and atrophic subjects. Dynamic B-mode US and shear wave elastography (SWE) videos of right GM muscles were performed in 32 healthy subjects and 18 atrophic patients with their ankle angles from 40° plantarflexion to 30° dorsiflexion by an isokinetic dynamometer. During muscle passive stretching induced by ankle rotation, consecutive muscle lengths were measured by automatically tracking the distal muscle-tendon junction positions in B-mode imaging frames using Hough transform and an active contour method. The corresponding elastic moduli were obtained using SWE imaging frames. The Gauss-Newton algorithm was used to estimate the parameters k, l0 and G0 from normalized elastic modulus-length curve. In-vivo experimental results showed that the measured muscle elastic modulus-length data fitted well to the proposed model with three estimated parameters for all subjects (0.942 < R2 < 0.997). The passive-elastic coefficient k was significantly higher for atrophic subjects compared with normal subjects (105.5 ± 45.3 versus 48.4 ± 16.0, p < 0.001). The proposed parameters allow further characterization of muscle essential mechanical properties and have a potential to become effective indexes for muscular disease diagnosis.