title: An adaptive strain estimator for elastography.
abstract: Elastography is based on the estimation of strain due to applied tissue compression. In conventional elastography, strain is computed from the gradient of the displacement estimates between gated pre- and postcompression echo signals. Gradient-based estimation methods are known to be susceptible to noise. In elastography, in addition to the electronic noise, a principal source of estimation error is the decorrelation of the echo signal as a result of tissue compression (decorrelation noise). Temporal stretching of postcompression signals previously was shown to reduce the decorrelation noise. In this paper, we introduce a novel estimator that uses the stretch factor itself as an estimator of the strain. It uses an iterative algorithm that adaptively maximises the correlation between the pre- and postcompression echo signals by appropriately stretching the latter. We investigate the performance of this adaptive strain estimator using simulated and experimental data. The estimator has exhibited a vastly superior performance compared with the conventional gradient-based estimator.
authors.affiliation: Ultrasonics Lab., Texas Med. Sch., Houston, TX.
authors.forename: S K
authors.initials: SK
authors.lastname: Alam
authors.forename: J
authors.initials: J
authors.lastname: Ophir
authors.forename: E E
authors.initials: EE
authors.lastname: Konofagou