Estimation of two-dimensional strain rate based on high frame rate ultrasound imaging method

Abstract

Current SR estimation methods that use speckle tracking technique are based on conventional delay-and-sum (D&S) imaging method with multiple transmissions, which causes skewed image of moving object resulting in inaccurate SR. To overcome the problem, a method to combine high frame rate imaging method (HFR) with speckle tracking technique was proposed. Using only one or a few transmissions for each image; the new method can obtain a snapshot of moving targets, avoiding the skewing problem in D&S method that uses 91 transmissions. Studies, with simulated and experimental echo data respectively, were performed to verify the method. The new method is compared with D&S imaging method also using one transmission so that the skewing problem existing for D&S with multiple transmissions can be avoided. Both plane wave (PW) and limited diffraction beam (LDB) were studied for the HFR imaging method. Results show that the new method has comparable velocity errors and SR accuracy with the D&S method when using one transmission. Moreover, the new method can measure high velocity in application such as blood flow measurement. Using a full view of the heart image, SR can be localized and then estimated.