Comparisons of image quality factors for phase aberration correction with diffuse and point targets: theory and experiments.

The use of several alternative image-brightness-based quality factors for phase aberration correction with diffuse and point targets in coherent ultrasonic imaging systems is explored. The factors are similar to the sharpness functions proposed by R.A. Muller et al. (1974) for incoherent imaging systems. Different region of interest (ROI) sizes are used to compare the quality factors. Good agreement is found between theoretical analysis, computer simulations, and phantom experiments. For a point target, the mean of the magnitude of echo signals is inferior to the other studied quality factors in correcting phase aberration. All of the quality factors studied are similar in their ability to correct phase errors for diffuse target images.