Speckle reduction with multitaper approach to improve B/A imaging

Matthieu Toulemonde , François Varray (1) , Piero Tortoli (2) , Christian Cachard (1) , Olivier Basset (1)

1 Imagerie Ultrasonore
2 Electronics and Telecommunications Department

During the propagation of an ultrasound wave, harmonic frequencies appear due to the nonlinear property of the tissue. When tissue characterization is concerned, the non-linear parameter B/A can be interesting to differentiate normal and pathological tissues. A recent paper proposes an extended comparative method (ECM) to image the B/A parameter in inhomogeneous media. However, the accuracy of this approach is limited by the presence of speckle in the image. We propose to improve the B/A parameter estimation in radio frequency image thanks to a speckle reduction approach based on a multitaper compounding method [Jensen et al., IEEE International Ultrasonics Symposium 2011]. Different orthogonal apodization functions (Slepian sequences) in reception are used to provide orthogonal tapers. In spite of a reduction of the lateral and axial resolution, about two to four times for the lateral resolution, the combination of the different images results in a significant increase of the SNR, 1,6 to 2,3 for the second harmonic, which allow a better estimation of the B/A parameter. The efficiency of the technique is validated on simulated data provided by CREANUIS [Varray et al., IEEE International Ultrasonics Symposium 2010] simulator and experimental results will be presented.

Mots clés: Nonlinear parameter; Speckle reduction

Domaines: Acoustique [physics.class-ph]

Matthieu Toulemonde, François Varray, Piero Tortoli, Christian Cachard, Olivier Basset. Speckle reduction with multitaper approach to improve B/A imaging. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00810810⟩