Department of Circulation and Medical Imaging at the Norwegian University of Science and Technology.
IEEE Trans Ultrason Ferroelectr Freq Control. 2011 Feb;58(2):290-7. doi: 10.1109/TUFFC.2011.1806.
SURF contrast imaging, as described previously in the literature, is a contrast agent detection technique achieved by processing of the received signals from transmitted dual frequency band pulse complexes with overlapping high-frequency (HF) and low-frequency (LF) pulses. The transmitted HF pulses are used for image reconstruction, whereas the transmitted LF pulses are used to manipulate the scattering properties of the contrast agent. As with harmonic contrast agent detection techniques, nonlinear wave propagation will, in most situations, also limit the specificity with the SURF contrast technique when transmitting overlapping HF and LF pulses. The present paper proposes an alternative SURF contrast imaging technique using transmit dual frequency band pulse complexes with non-overlapping HF and LF pulses. If the frequency of the LF manipulation pulse is close to the bubble resonance frequency, numerical simulations indicate a significant ring-down effect of the LF bubble radius response. Utilizing this bubble ring-down effect and transmitting the HF pulse just after the LF pulse, a contrast agent specificity approaching infinity accompanied by a contrast agent sensitivity only for contrast bubbles having resonance frequencies within a narrow frequency range may be obtained.
SURF 对比成像，如文献中所述，是一种通过处理发射的双频脉冲复合物的接收信号来实现的对比剂检测技术，其中重叠的高频 (HF) 和低频 (LF) 脉冲。发射的 HF 脉冲用于图像重建，而发射的 LF 脉冲用于操纵对比剂的散射特性。与谐波对比剂检测技术一样，在大多数情况下，当发射重叠的 HF 和 LF 脉冲时，非线性波传播也会限制 SURF 对比技术的特异性。本文提出了一种替代的 SURF 对比成像技术，使用发射双频带脉冲复合物，其中 HF 和 LF 脉冲不重叠。如果 LF 调制脉冲的频率接近气泡的共振频率，数值模拟表明 LF 气泡半径响应的显著的衰减效应。利用这种气泡的衰减效应，并在 LF 脉冲之后立即发射 HF 脉冲，可以获得接近无限的对比剂特异性，同时仅对具有共振频率在较窄频率范围内的对比气泡具有对比剂敏感性。
