Abstract
Coded excitation is useful for ultrasound contrast imaging to increase penetration and SNR, and improve the contrast to tissue ratio (CTR). The waveform of bubble response depends greatly on bubble size, the frequency and bandwidth of the excitation chirp signal. This makes the pulse compression filter based on square-law be wrong for bubbles with changing sizes. In this paper, an adaptive pulse compression (APC) filter for the second harmonic of microbubble with varying size distribution is proposed. The APC filter is designed based on the estimated power spectrum of the received bubble harmonic echoes. Theoretical analysis and simulation studies are presented for evaluating performance of the APC filter. For monodisperse bubble, the power improvement factor of the APC filter can be more than 20 dB.
Highlights
Coded excitation is useful for ultrasound imaging to increase penetration and SNR
Coded excitation is useful for ultrasound contrast imaging to increase penetration and SNR, and improve the contrast to tissue ratio (CTR)
The adaptive pulse compression (APC) filter is designed based on the estimated power spectrum of the received bubble harmonic echoes
Summary
Coded excitation is useful for ultrasound imaging to increase penetration and SNR. For improving the CTR (contrast to tissue ratio) in ultrasound contrast imaging, coded excitation is preferred . Borsboom et al suggest a nonlinear compression filter to do pulse compression for bubble second harmonic imaging [1] They made use of a square law (SQL) model to design the pulse compression filter, which had the twice instantaneous frequency of the transmitted chirp. Microbubbles have a time-varying size distribution in the perfusion region of interest, bubbles of different sizes respond to chirp excitation differently This will lead to restrictions on the performance of the SPC filter. We propose an adaptive pulse compression filter to compress the second harmonic of bubble while microbubbles have a time varying size distribution. The APC filter is designed based on the estimated power spectrum of the received bubble harmonic echoes It changes the pulse compression filter for bubble of different sizes adaptively to optimize the output power. The performance of the APC filter is studied using simulation signals generated by BubbleSim [4]
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.