基于超声剪切波弹性成像定量评估杜氏肌营养不良患儿小腿三头肌肌肉硬度的研究

关键词：杜氏肌营养不良  超声剪切波弹性成像  小腿三头肌  肌肉硬度  运动功能评估

Keywords:Duchenne muscular dystrophy  shear wave elastography  triceps surae  muscle stiffness  motor function assessment

摘要：

      摘要 目的：应用超声剪切波弹性成像（SWE）技术定量分析杜氏肌营养不良（DMD）患儿小腿三头肌硬度特征，并探讨其与运动功能障碍的相关性。 方法：采用横断面比较分析研究，纳入35例DMD患儿及20例健康儿童对照。采用SWE技术在踝关节放松位和中立位下测量腓肠肌内侧头（MG）、外侧头（LG）及比目鱼肌（SM）的杨氏模量值以定量评价肌肉硬度，并同时进行运动功能评估（MFM、计时测试）及踝关节活动度测量。通过线性混合效应模型分析评估组别、部位和体位对杨氏模量值的影响，Spearman检验评估硬度参数与临床功能指标的相关性。 结果：DMD患儿踝背屈活动显著受限（P＜0.001）。病例组MG在中立位杨氏模量值（98.04±62.20 kPa）显著高于对照组（41.18±13.10 kPa）（P＜0.001），且变异系数达63.4%。线性混合效应模型分析显示，组别、部位、体位及其所有交互作用均对杨氏模量值有显著影响（均P＜0.001）。病例组MG呈现体位依赖性硬度变化，在放松位的杨氏模量显著低于对照组（β=-57.08， P＜0.001），而在中立位显著升高（β=56.84，P＜0.001）。相关性分析显示，中立位MG杨氏模量值与10m步行/跑时间呈正相关（r=0.35，P＜0.05），与MFM总分呈负相关（r=﹣0.37，P＜0.05）。MFM-D3评分与放松位MG（r=﹣0.50）、LG（r=﹣0.36）及中立位SM（r=﹣0.55）均呈显著负相关（P＜0.05）。 结论：SWE技术可客观反映DMD患儿小腿三头肌硬度特征。腓肠肌内侧头在中立位的硬度显著增高，且具有明显体位依赖性。肌肉硬度与运动功能障碍密切相关，提示SWE在评估肌肉力学特性及功能损害方面具有重要临床价值。

Abstract:

      Abstract Objective：To quantitatively characterize passive stiffness of the triceps surae in children with Duchenne muscular dystrophy （DMD） using shear wave elastography （SWE）， and to explore anatomical site-specific，posture-dependent variations and their associations with motor dysfunction. Method：In this cross-sectional study， 35 children with DMD and 20 healthy controls were enrolled. SWE measurements of Young's modulus were performed on the medial gastrocnemius （MG）， lateral gastrocnemius （LG）， and soleus muscle （SM） with the ankle in the relaxed and neutral positions. Concurrently， motor function assessments [motor function measure （MFM） scale， timed function tests] and ankle dorsiflexion range of motion （ROM） was evaluated. Linear mixed-effects models were applied to analyze the effects of group， muscle site， and posture on Young's modulus， while Spearman's correlation analysis was used to assess associations between stiffness parameters and clinical outcomes. Result：DMD patients exhibited significantly restricted ankle dorsiflexion （P<0.001）. The MG in the DMD group demonstrated markedly higher Young's modulus at neutral position （98.04±62.20 kPa vs. 41.18±13.10 kPa in controls， P<0.001） with a coefficient of variation （CV） of 63.4%. Mixed-effects models revealed significant main effects and interactions of group， muscle site， and posture on modulus values （all P<0.001）. Notably， DMD-MG displayed posture-dependent stiffness alterations： lower modulus than controls in the relaxed position （β=﹣57.08， P<0.001） but significantly elevated in the neutral position （β=56.84， P<0.001）. Neutral-position MG stiffness was positively correlated with 10-meter walk/run test （r=0.35， P<0.05） and negatively with total MFM score （r=﹣0.37， P<0.05）. MFM-D3 subscores showed significant negative correlations with relaxed-position MG （r=﹣0.50）， LG （r=﹣0.36）， and neutral-position SM stiffness （r=﹣0.55） （all P<0.05）. Conclusion：SWE may objectively characterize the stiffness of the triceps surae in children with DMD. The medial gastrocnemius shows significantly increased stiffness in the neutral position with notable position dependency. Muscle stiffness is closely associated with motor dysfunction， indicating that SWE has important clinical value in assessing biomechanical properties and functional impairment.