ESTIMATING TISSUE STRAIN FROM SIGNAL DECORRELATION USING THE CORRELATION-COEFFICIENT

A simple relationship between the correlation coefficient and the appl ied strain, applicable only at low strains, is presented in this artic le. This relationship is derived for a Gaussian modulated cosine point spread function. The performance of the strain estimator is analyzed using a theoretical expression for the correlation coefficient along w ith simulation and experimental results. Both the theoretical and simu lation results diverge from the ideal relationship between the strain and the correlation coefficient as the applied strain is increased. Si mulation results illustrate that the strain estimate obtained using th e correlation coefficient is a biased estimate with a large variabilit y. Experimental results, however, illustrate that strain estimation us ing the 1-D correlation coefficient estimate is applicable only at hig h signal-to-noise ratios in the radiofrequency signal and in the absen ce of lateral and elevational signal decorrelation. Copyright (C) 1996 World Federation for Ultrasound in Medicine and Biology.