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Increasing Accuracy of Tissue Shear Modulus Reconstruction Using Ultrasonic Strain Tensor Measurement

Lateral Modulation and Regularization
Part of the Acoustical Imaging book series (ACIM, volume 29)

Abstract

Previously, we developed three displacement vector measurement methods, i.e., the multidimensional cross-spectrum phase gradient method (MCSPGM), the multidimensional autocorrelation method (MAM), and the multidimensional Doppler method (MDM). To increase the accuracies and stabilities of lateral and elevational displacement measurements, we also developed spatially variant, displacement component-dependent regularization. In particular, the regularization of only the lateral/elevational displacements is advantageous for the lateral unmodulated case. The demonstrated measurements of the displacement vector distributions in experiments using an inhomogeneous shear modulus agar phantom confirm that displacement-component-dependent regularization enables more stable shear modulus reconstruction. In this report, we also review our developed lateral modulation methods that use Parabolic functions, Hanning windows, and Gaussian functions in the apodization function and the optimized apodization function that realizes the designed point spread function (PSF). The modulations significantly increase the accuracy of the strain tensor measurement and shear modulus reconstruction (demonstrated using an agar phantom).

Key words

Shear modulus reconstruction Displacement vector measurement Strain tensor measurement MAM MDM MCSPGM Spatially variant regularization Displacement-component-dependent regularization Lateral modulation Agar phantom 

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Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  • C. Sumi
    • 1
  1. 1.Faculty of Science and TechnologySophia UniversityTokyoJapan

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