Frequency Diversity Speckle Processing
by Steve M. Gehlbach (Kesa Corporation) and F. Graham Sommer (Stanford University).
Published by the Academic Press, 1987. Ultrasonic Imaging 9, pp92-105 (1987).
Ultrasonic waveform data from a tissue mimicking phantom containing low contrast targets was digitized, stored and processed prior to creating and displaying ultrasonic images. Speckle reduction was performed by digital filtering of the waveform data with appropriately spaced and weighted digital filters, prior to both coherent and incoherent image averaging. The resultant images showed increased signal-to-noise ratios, consistent with theory. Better definition of low contrast target boundaries was noted in the processed, compared to the unprocessed, images. Incoherent and coherent processing were investigated, and appeared to be equivalent.