Moraes R, Evans D H
Division of Medical Physics, Faculty of Medicine, University of Leicester, UK.
Ultrasound Med Biol. 1996;22(1):129-37. doi: 10.1016/0301-5629(95)02027-6.
Quadrature phase detection is widely used in ultrasound Doppler systems to obtain directional information about flow velocities in blood vessels. The presence of phase and/or gain imbalance between the quadrature outputs produces crosstalk between the forward and reverse channels which may introduce errors into mean and maximum velocity estimates and hamper the interpretation of sonograms. This technical note describes the assessment of the crosstalk in a commercial pulsed-wave Doppler system, and suggests methods of compensation for the causative imbalance which can be implemented using digital signal processing techniques. Examples of applying these methods to the outputs of the commercial system are given.
正交相位检测在超声多普勒系统中被广泛应用，以获取血管中血流速度的方向信息。正交输出之间存在相位和/或增益不平衡会在正向和反向通道之间产生串扰，这可能会在平均速度和最大速度估计中引入误差，并妨碍对超声图像的解读。本技术说明描述了对商用脉冲波多普勒系统中串扰的评估，并提出了补偿引起不平衡的方法，这些方法可使用数字信号处理技术来实现。给出了将这些方法应用于商用系统输出的示例。
