Viscoelasticity-based MR elastography of skeletal muscle
Viscoelasticity-based MR elastography of skeletal muscle
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DOI：
10.1088/0031-9155/55/21/007
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发表时间：
2010-11-07
影响因子：
3.5
通讯作者：
Sack, Ingolf
中科院分区：
文献类型：
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作者：
Klatt, Dieter;Papazoglou, Sebastian;Sack, Ingolf
建立了一种活体多频磁共振弹性成像(MRE)方法，用于研究人骨骼肌在不同收缩状态下的粘弹性特性。将25~62.5赫兹的低频剪切振动同步诱发到7名志愿者的股骨肌肉中，通过编码平行于肌纤维的快横向剪切波分量，在横切面上进行测量。所谓的弹跳盆模型被用来从松弛和负重肌肉的复剪切模的色散函数中推导出两个粘弹性常数u和α。代表平行于肌纤维的剪切弹性，所有受试者收缩时的Mu从2.68+/-0.23kPa升至3.87+/-0.50kPa.此外，阿尔法随着负荷的变化而变化，表明肌肉机械网络的几何形状从放松(阿尔法=0.253+/-0.009)变为收缩(阿尔法=0.270+/-0.009)。这些结果为今后使用流变学参数评估肌肉功能障碍提供了参考。
An in vivo multifrequency magnetic resonance elastography (MRE) protocol was developed for studying the viscoelastic properties of human skeletal muscle in different states of contraction. Low-frequency shear vibrations in the range of 25-62.5 Hz were synchronously induced into the femoral muscles of seven volunteers and measured in a cross-sectional view by encoding the fast-transverse shear wave component parallel to the muscle fibers. The so-called springpot model was used for deriving two viscoelastic constants, mu and alpha, from the dispersion functions of the complex shear modulus in relaxed and in loaded muscle. Representing the shear elasticity parallel to the muscle fibers, mu increased in all volunteers upon contraction from 2.68 +/- 0.23 kPa to 3.87 +/- 0.50 kPa. Also alpha varied with load, indicating a change in the geometry of the mechanical network of muscle from relaxation (alpha = 0.253 +/- 0.009) to contraction (alpha = 0.270 +/- 0.009). These results provide a reference for a future assessment of muscular dysfunction using rheological parameters.