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Real Time Ultrasound Elastography Based on Phase Shift |
1 Department of Biomedical Engineering, Shenzhen University, Shenzhen 518060, China
2 NationalRegional Key Technology Engineering Laboratory for Medical Ultrasound, Shenzhen 518060, China
3 Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, Shenzhen 518060, China |
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Abstract Quasistatic ultrasound elastography is an imaging modality to track tissue motion from ultrasonic signals before and after compression to image tissue elasticity. In this study, we presented a framework combined with block matching algorithm (BMA) and phase shift method (PS) for displacement estimation. BMA was first applied to the radio frequency (RF) signals, the displacements obtained were then used as a prior estimates of the PS method to calculate a more precision axial displacements. The performance of the algorithm was evaluated with synthesis data, and the result showed that both SNRe and CNRe of our method were significantly higher than those of PSPE method. In the case of strain value at 2% and Poissons ratio 0.49, the SNRe of PSPE and new algorithm were 3.82 and 10.85, respectively. The proposed algorithm was further validated using both elasticity phantom data and clinical data. Results showed that our method was robust to relatively complex tissue motions. The proposed algorithm was also fast, which provides real time strain images.
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