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Parker Medical Imaging Research

The New View of Tissue Scattering

Illustration of complex architecture of liver.

Do we really know what causes scattering of ultrasound from normal soft tissues such as the liver, thyroid, and prostate? Commonly, the answer is formulated around the properties of spherical scatterers, related to cellular shapes and sizes. However, our alternative view is that the closely packed cells forming the tissue parenchyma create the reference media, and the long cylindrical-shaped fluid vessels serve as the scattering sites. Assuming a weak scattering (Born approximation) for the vessels, in an isotropic, fractal branching pattern, some simple predictions can be made about the nature of backscatter as a function of frequency in soft tissues. We also have derived mathematical models for the first order statistics (the histogram) of echoes. These models are a major departure from the conventional views, but seem to capture the behavior seen in millions of B-scans obtained each year.

Journal Articles

  1. Burr, Lomax, Pareto, and logistic distributions from ultrasound speckle
    K. J. Parker and S. S. Poul
    Ultrasonic Imaging, vol. 42, no. 4-5 , pp. 203 -212  (2020). View PDF
  2. Speckle from branching vasculature: dependence on number density
    K. J. Parker and S. S. Poul
    J Med Imaging, vol. 7, no. 2 , pp. 027001-1 -027001-12  (2020). View PDF
  3. Liver backscatter and the hepatic vasculature's autocorrelation function
    J. J. Carroll-Nellenback, R. J. White, R. W. Wood, and K. J. Parker
    Acoustics, vol. 2, no. 1 , pp. 3 -12  (2020). View PDF
  4. The first order statistics of backscatter from the fractal branching vasculature
    K. J. Parker
    J Acoust Soc Am, vol. 146, no. 5 , pp. 3318 -3326  (2019). View PDF
  5. Shapes and distributions of soft tissue scatterers
    K. J. Parker
    Phys Med Biol, vol. 64, no. 17 , pp. 175022-1 -175022-15  (2019). View PDF
  6. The 3D spatial autocorrelation of the branching fractal vasculature
    K. J. Parker, J. J. Carroll-Nellenback, and R. W. Wood
    Acoustics, vol. 1, no. 2 , pp. 369 -381  (2019). View PDF