Gradient based elastic property reconstruction in digital image correlation elastography

Aim: A Conjugate Gradient implementation of the Digital Image Correlation Elastography method is presented. Method: The gradient is calculated using the adjoint method, requiring only two forward solutions regardless of the number of mechanical properties to reconstruct. A power-law based multi-frequency viscoelastic model is used to relate the reconstructed mechanical properties and the Digital Image Correlation surface displacement measurements. Result: The method is tested against harmonic surface motion fields generated through numerical simulation and measured on a silicon phantom. Conclusion: Reconstruction results show the ability of the gradient reconstruction method to detect stiff internal inclusions in simulated and phantom data.