Data from: Repeatability of rotational 3D shear wave elasticity imaging measurements in skeletal muscle

Shear wave elasticity imaging (SWEI) usually assumes an isotropic material; however, skeletal muscle is typically modeled as a transversely isotropic material with independent shear wave speeds in the directions along and across the muscle fibers. To capture these direction-dependent properties, we implemented a rotational 3D-SWEI system which measures the shear wave speed both along and across the fibers in a single 3D-acquisition, with automatic detection of the muscle fiber orientation. Herein, we tested and examined the repeatability of this system's measurements in the vastus lateralis of 10 healthy volunteers. The average coefficient of variation of the measurements from this 3D-SWEI system was 5.3% along the fibers and 8.1% across the fibers. When compared to estimated respective 2D-SWEI values of 16.0% and 83.4%, these results suggest using 3D-SWEI has potential to improve the precision of SWEI measurements in muscle. Additionally, we observed no significant difference in shear wave speed between the dominant and non-dominant legs along (p=0.26) or across (p=0.65) the muscle fibers.

剪切波弹性成像（Shear wave elasticity imaging, SWEI）通常假设材料为各向同性，但骨骼肌通常被建模为横向各向同性材料，其沿肌纤维方向与跨肌纤维方向的剪切波速度互不相同。为捕捉这种方向依赖性特征，本研究搭建了一套旋转式三维剪切波弹性成像系统，可在单次三维采集过程中同时测量沿肌纤维与跨肌纤维方向的剪切波速度，并自动检测肌纤维方向。随后，本研究对10名健康志愿者的股外侧肌进行了测试，验证了该系统测量结果的可重复性。该三维剪切波弹性成像系统的测量平均变异系数为：沿肌纤维方向5.3%，跨肌纤维方向8.1%；相较于二维剪切波弹性成像（2D-SWEI）的对应估算值16.0%与83.4%，上述结果表明，采用三维剪切波弹性成像有望提升骨骼肌剪切波弹性成像测量的精度。此外，本研究还发现，沿肌纤维方向（p=0.26）与跨肌纤维方向（p=0.65），优势侧与非优势侧下肢的剪切波速度均无显著差异。