A NEW ELASTOGRAPHIC METHOD FOR ESTIMATION AND IMAGING OF LATERAL DISPLACEMENTS, LATERAL STRAINS, CORRECTED AXIAL STRAINS AND POISSONS RATIOS IN TISSUES

A major disadvantage of the current practice of elastography is that o nly the axial component of the strain is estimated. The lateral and el evational components are basically disregarded, yet they corrupt the a xial strain estimation by inducing decorrelation noise. In this paper, we describe a new weighted interpolation method operating between nei ghboring RF A-lines for high precision tracking of the lateral displac ement. Due to this high lateral-tracking precision, quality lateral el astograms are generated that display the lateral component of the stra in tensor. These precision lateral-displacement estimates allow a fine correction for the lateral decorrelation that corrupts the axial esti mation, Finally, by dividing the lateral elastogram by the axial elast ogram, we are able to produce a new image that displays the distributi on of Poisson's ratios in the tissue. Results are presented from finit e-element simulations and phantoms as well as in vitro and in vivo exp eriments, (C) 1998 World Federation for Ultrasound in Medicine & Biolo gy.