Speckle tracking for multi-dimensional flow estimation

Speckle tracking methods overcome the major limitations of current Doppler methods for how imaging and quantification: angle dependence and aliasing. In this paper, we review the development of speckle tracking, with particul ar attention to the advantages and limitations of two-dimensional algorithm s that use a single transducer aperture. Ensemble tracking, a recent speckl e tracking method based upon parallel receive processing, is described. Exp erimental results with ensemble tracking indicate the ability to measure la minar flow in a phantom at a beam-vessel angle of 60 degrees, which had not been possible with previous 2D speckle tracking methods. Finally, importan t areas for future research in speckle tracking are briefly summarized. (C) 2000 Elsevier Science B.V. All rights reserved.