包膜气泡类超声造影剂非线性检测的一种新方法

Detection Nonlinearity from Microbubble Contrast Agents

研究了选择性检测包膜超声造影剂的一种新方法———脉冲逆转多普勒技术.通过对含有造影剂的部位发射前后逆转的超声脉冲,得到多普勒谱并形成了线性、非线性谱区,它们分别来自回波区运动的线性、非线性散射源.实验证明,该技术检测的造影剂/线性媒质对比度高于采用相同发射脉冲数的谐波技术3～10dB,宽带条件下该技术比常规多普勒技术的对比度最多可提高16dB,适合于在静止或运动的线性组织杂波背景下,对含有非线性造影剂的中小血管血流进行测量与成像.

The pulse inversion Doppler technique is applied for detecting ultrasound contrast agents through their nonlinear behavior. The linear and nonlinear scattering from the tissue can be separated from the Doppler spectrum. In vitro study showed that this technique improves the agent to tissue contrast by 3 to 10 dB as compared with the harmonic technique. A factor up to 16 dB in contrast gained can be achieved when compared with the broadband conventional Doppler technique. Contrast improvement is thus made possible for imaging of blood flow in microvasculature with high clutter tissues.