A QUALITY-GUIDED DISPLACEMENT TRACKING ALGORITHM FOR ULTRASONIC ELASTICITY IMAGING
L.Chen, G.M. Treece, J.E. Lindop, A.H. Gee and R.W. Prager
January 2008
Displacement estimation is a key step in the evaluation of tissue elasticity by quasistatic strain imaging. An efficient displacement estimation process may incorporate a tracking strategy that initializes each point according to its neighbours' displacements and then performs a localized search. This increases the accuracy and reduces the computation expense compared with exhaustive search. However, simple tracking strategies fail when the target displacement map exhibits complex structure. For example, there may be discontinuities and regions of indeterminate displacement caused by decorrelation between the pre- and post-deformation radio frequency (RF) echo signals. This paper introduces a novel displacement tracking algorithm, with an intelligent search strategy guided by a data quality indicator. Comparisons with existing methods show that the proposed algorithm is more robust across a range of displacement distributions, RF window lengths and noise levels.
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