Estimation of a dense velocity field based on the statistics of dynamic speckle
This article presents a new technique for flow velocity estimation from ultrasound image sequences. The method is based on the analysis of the temporal statistics of the speckle pattern in motion. We demonstrate that the biased local temporal variance (LTV) of a single pixel within an image of dynamic speckle is related to velocity. This allows us to estimate the total velocity magnitude without the requirement of neither block matching nor autocovariance estimation. A new estimator, asymptotically without bias, called LTV is presented. Results conducted on experimental B mode sequences (40 MHz) of blood mimicking fluid with calibrated velocities are presented. Performances of the estimator are studied and results show good agreement with the statistical model. Magnitude of the 3D velocity vector in the range of 0.12 mm/s have been estimated with a standard deviation error of less than 12%. The validity of the method and its limitations are then discussed.  2010 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 20, 268-276, 2010
speckle flow velocity estimation ultrasound imaging decorrelation statistical estimation