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Parker Medical Imaging Research

The Microchannel Flow Model

Recent advances have enabled a new wave of biomechanics measurements, and have renewed interest in selecting appropriate rheological models for soft tissues such as the liver, thyroid, and prostate. The microchannel flow model was recently introduced to describe the linear response of tissue to stimuli such as stress relaxation or shear wave propagation. This model postulates a power law relaxation spectrum that results from a branching distribution of vessels and channels in normal soft tissue such as liver. In this work, the derivation is extended to determine the explicit link between the distribution of vessels and the relaxation spectrum. The microchannel flow model explains the dramatic changes in tissue “stiffness” caused by changes in the vasculature, including rapid vasodilation or vasoconstriction.

A microchannel flow model for soft tissue elasticity
K. J. Parker
Phys Med Biol, vol. 59, no. 15, pp. 4443-4457 (2014).  View Online


Journal Articles


  1. Are rapid changes in brain elasticity possible?
    K. J. Parker
    Physics in Medicine and Biology, vol. 62, no. 18 , pp. 7425 -7439  (2017). View Online
  2. The microchannel flow model under shear stress and high frequencies
    K. J. Parker
    Physics in Medicine and Biology, vol. 62, no. 8 , pp. N161 -N167  (2017). View Online
  3. Shear wave dispersion behaviors of soft, vascularized tissues from the microchannel flow, model
    K. J. Parker, J. Ormachea, S. A. McAleavey, R. W. Wood, J. J. Carroll-Nellenback, and R. K. Miller
    Physics in Medicine and Biology, vol. 61, no. 13 , pp. 4890 -4903  (2016). View Online
  4. Biological effects of low frequency strain: physical descriptors
    E. L. Carstensen, K. J. Parker, D. Dalecki, and D. Hocking
    Ultrasound in Medicine and Biology, vol. 42, no. 1 , pp. 1 -15  (2016). View Online
  5. Oestreicher and elastography
    E. L. Carstensen and K. J. Parker
    Journal of the Acoustical Society of America, vol. 138, no. 4 , pp. 2317 -2325  (2015). View Online
  6. What do we know about shear wave dispersion in normal and steatotic livers?
    K. J. Parker, A. Partin, and D. J. Rubens
    Ultrasound in Medicine and Biology, vol. 41, no. 5 , pp. 1481 -1487  (2015). View Online
  7. Experimental evaluations of the microchannel flow model
    K. J. Parker
    Physics in Medicine and Biology, vol. 60, no. 11 , pp. 4227 -4242  (2015). View Online
  8. Could linear hysteresis contribute to shear wave losses in tissues?
    K. J. Parker
    Ultrasound in Medicine and Biology, vol. 41, no. 4 , pp. 1100 -1104  (2015). View Online
  9. A microchannel flow model for soft tissue elasticity
    K. J. Parker
    Phys Med Biol, vol. 59, no. 15 , pp. 4443 -4457  (2014). View Online
  10. Real and causal hysteresis elements
    K. J. Parker
    Journal of the Acoustical Society of America, vol. 135, no. 6 , pp. 3381 -3389  (2014). View Online
  11. Physical models of tissue in shear fields
    E. L. Carstensen and K. J. Parker
    Ultrasound in Medicine and Biology, vol. 40, no. 4 , pp. 655 -674  (2014). View Online
  12. The Guassian shear wave in a dispersive medium
    K. J. Parker and N. Baddour
    Ultrasound in Medicine and Biology, vol. 40, no. 4 , pp. 675 -684  (2014). View Online
  13. Congruence of imaging estimators and mechanical measurements of viscoelastic properties of soft tissues
    M. Zhang, B. Castaneda, Z. Wu, P. Nigwekar, J. Joseph, D. J. Rubens, and K. J. Parker
    Ultrasound Med Biol, vol. 33, no. 10 , pp. 1617 -1631  (2007). View PDF