Combined phase screen aberration correction and minimum variance beamforming in medical ultrasound
Autor: | Mahsa Sotoodeh Ziksari, Babak Mohammadzadeh Asl |
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Rok vydání: | 2016 |
Předmět: |
Beamforming
Acoustics and Ultrasonics Phase screen business.industry Image quality Computer science Phantoms Imaging Signal Processing Computer-Assisted 01 natural sciences 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine Transducer Minimum-variance unbiased estimator Optics Contrast-to-noise ratio Robustness (computer science) 0103 physical sciences Image Processing Computer-Assisted Computer Simulation business 010301 acoustics Adaptive beamformer Algorithms Ultrasonography |
Zdroj: | Ultrasonics. 75 |
ISSN: | 1874-9968 |
Popis: | In recent years, applying adaptive beamforming to ultrasound imaging improves image quality in terms of resolution and contrast. One of the best adaptive beamformers in this field is the minimum variance (MV) beamformer which presents better resolution and edge definition compared to the traditional delay-and-sum (DAS) beamformer. However, in real situations, sound-velocity inhomogeneities cause phase aberration which leads to ambiguity in targets’ location and degradation in resolution. This effect is a fundamental obstacle to utilize advantages of MV beamformer, although, in aberrating medium MV beamformer results in better performance compared to DAS. In this paper, two different levels of phase screens have been applied to simulate aberrator layers located close to the transducer. Also, prior to beamforming process, a conventional correction technique based on phase screen model is used. Simulations are performed in majority resolution of MV which has the lowest robustness. The results demonstrate that applying this correction method can retrieve the efficiency of the MV beamformer. Moreover, the method improves the performance of the MV in both terms of resolution and contrast. As corrected MV achieved at least 22% improvement in sidelobe reduction and 24% increase in contrast to noise ratio (CNR) with respect to the DAS corrected data. Also, according to experimental dataset 17% enhancement in CNR is yielded by MV. |
Databáze: | OpenAIRE |
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