Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan.
IEEE Trans Ultrason Ferroelectr Freq Control. 2011 Feb;58(2):349-56. doi: 10.1109/TUFFC.2011.1812.
Golay-encoded excitation in combination with the third harmonic (3f₀) transmit phasing is examined for both signal-to-noise ratio (SNR) and contrast-to-tissue ratio (CTR) improvements in harmonic imaging of contrast microbubbles. To produce the cancellation pair of tissue harmonic signal in 3f₀ transmit phasing, the phase of the bit waveform is properly designed for both the fundamental and the 3f₀ transmit signals to provide the Golay encoding of the received harmonic responses. Results indicate that the proposed Golay excitation can effectively suppress the tissue harmonic amplitude to increase CTR. Meanwhile, the SNR of the contrast harmonic signal also improves because of the elongated waveform of Golay excitation. Nevertheless, the generation of marked range side-lobes of the bubble region would degrade the achievable SNR improvement and the image contrast, especially when the bit of Golay excitation increases. The range side-lobes could result from the nonlinear resonance of the microbubbles that interferes with the phase modulation of the Golay encoding.
戈莱编码激励与三次谐波（3f₀）发射相位结合，用于研究对比微泡谐波成象中信噪比（SNR）和对比组织比（CTR）的改善。为了在 3f₀发射相位中产生组织谐波信号的抵消对，适当设计位波形的相位，以便为基本和 3f₀发射信号提供接收谐波响应的戈莱编码。结果表明，所提出的戈莱激励可以有效地抑制组织谐波幅度，从而提高 CTR。同时，由于戈莱激励的波形延长，对比谐波信号的 SNR 也得到了提高。然而，由于气泡区域的标记距离旁瓣的产生，会降低可实现的 SNR 改善和图像对比度，特别是当戈莱激励的位增加时。距离旁瓣可能是由于微泡的非线性共振干扰了戈莱编码的相位调制而产生的。
