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Measurement of muscle activity with magnetic resonance elastography

      Abstract

      Objective. To non-invasively determine muscle activity.
      Design. A correlation analysis study.
      Background. Electromyography is traditionally used to measure the electrical activity of a muscle and can be used to estimate muscle contraction intensity. This approach, however, is limited not only in terms of the volume of tissue that can be monitored, but must be invasive if deep lying muscles are studied. We wished to avoid these limitations and used magnetic resonance elastography in an attempt to non-invasively determine muscle activity. This novel approach uses a conventional MRI system. However, in addition to the imaging gradients, an oscillating, motion sensitizing field gradient is applied to detect mechanical waves that have been generated within the tissue. The wavelength correlates with the stiffness of the muscle and hence with the activity of the muscle.
      Methods. Six volunteers (mean age: 30.1 years, range: 27–36 years) without orthopedic or neuromuscular abnormalities, lay supine with their legs within the coil of a MRI scanner. The wavelengths of mechanically generated shear waves in the tibialis anterior, medial and lateral head of the gastrocnemius and the soleus were measured as the subjects resisted ankle plantar-flexing (8.2 and 16.4 nm) and dorsi-flexing (20.2 and 40.4 nm) moments. The findings were then compared to EMG data collected under the same loading conditions.
      Results. Magnetic resonance elastography wavelengths were linearly correlated to the muscular activity as defined by electromyography. (TA, R2=0.89, P=0.02; MG, R2=0.82, P=0.05; LG, R2=0.88, P=0.03; S, R2=0.90, P=0.02)
      Conclusions. Magnetic resonance elastography may be a promising tool for the non-invasive determination of muscle activity.
      Relevance Magnetic resonance elastography has potential as the basis for a new non-invasive approach to study in vivo muscle function.

      Keywords

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      References

        • Basford J.
        • Jenkyn T.
        • An K.
        • Ehman R.
        • Heers G.
        • Kaufman K.
        Evaluation of healthy and diseased muscle with magnetic resonance elastography.
        Arch. Phys. Med. Rehabil. 2002; 83: 1530-1536
        • Bishop J.
        • Poole G.
        • Leitch M.
        • Plewes D.
        Magnetic resonance imaging of shear wave propagation in excised tissue.
        J. Magn. Reson. Imaging. 1998; 8: 1257-1265
        • Dresner M.
        • Rose G.
        • Rossman P.
        • Muthupillai R.
        • Manduca A.
        • Ehman R.
        Magnetic resonance elastography of skeletal muscle.
        J. Magn. Reson. Imaging. 2001; 13: 269-276
        • Ettema G.
        • Huijing S.
        Skeletal muscle stiffness in static and dynamic contractions.
        J. Biomech. 1994; 27: 1361-1368
        • Hagberg M.
        Muscular endurance and surface electromyogram in isometric and dynamic exercise.
        J. Appl. Physiol. 1981; 51: 1-7
        • Kruse S.
        • Smith J.
        • Lawrence A.
        • Dresner M.
        • Manduca A.
        • Greenleaf J.
        • et al.
        Tissue characterization using magnetic resonance elastography: preliminary results.
        Phys. Med. Biol. 2000; 45: 1579-1590
      1. Lawrence, A., Muthupillai, R., Rossman, P., Smith, J., Manduca, A., Ehman, R., 1998. Proceedings of the International Society for Magnetic Resonance in Medicine 1, 233

        • Levinson S.
        • Shinagawa M.
        • Sato T.
        Sonoelastic determination of human skeletal muscle elasticity.
        J. Biomech. 1995; 28: 1145-1154
        • Moss R.
        • Halpern W.
        Elastic and viscous properties of the resting frog skeletal muscle.
        Biophys. J. 1977; 17: 213-228
        • Muthupillai R.
        • Lomas D.
        • Rossman P.
        • Greenleaf J.
        • Manduca A.
        • Ehman R.
        Magnetic resonance elastography by direct visualization of propagating acoustic strain waves.
        Science. 1995; 5232: 1854-1857
        • Muthupillai R.
        • Rossman P.
        • Lomas D.
        • Greenleaf J.
        • Riederer S.
        • Ehman R.
        Magnetic Resonance imaging of transverse acoustic strain waves.
        Magn. Reson. Med. 1996; 36: 266-274
        • Nieminen H.
        • Niemi J.
        • Takala E.
        • Viikari-Juntura E.
        Load sharing patterns in the shoulder during isometric flexion tasks.
        J. Biomech. 1995; 28: 555-566
        • Ophir J.
        • Cespedes I.
        • Ponnekante H.
        • Yazdi Y.
        • Li X.
        Elastography: a quantitative method for imaging the elasticity of biological tissues.
        Ultrasonic Imaging. 1991; 13: 11-134
        • Parker K.
        • Huang S.
        • Musulin R.
        • Lerner R.
        Tissue response to mechanical vibrations for sonoelasticity imaging.
        Ultrasound Med. Biol. 1994; 20: 27-33
        • Perrotto A.
        Anatomical Guide for the Electromyographer.
        third ed. Springfield, IL1994
        • Yamakoshi Y.
        • Satao J.
        • Sato T.
        Ultrasound imaging of internal vibration of soft tissue under forced vibration.
        IEEE Trans Ultrasound, Ferroelectrics, and Freq. Control. 1990; 37: 45-53