| 摘要 |
In a method and apparatus for ultrasound imaging of biological tissue using higher-order nonlinear signal components an ultrasound line is acquired at different excitation levels. The acquisition is repeated I times with identical beamforming parameters, but varying excitation level. All of the transmitted waveforms are nonlinearly distorted, but the degree of distortion depends on the excitation level, making it possible to extract individual nonlinear signal components by properly combining the received echo signals. A pre-computed estimation matrix, dependent on the order of an estimation model and the excitation levels, is stored in computer memory and used to compute the nonlinear components of interest. The real-time calculations reduce to a linear combination of the received echo signals. A further reduction in computational load can be achieved if one is interested in only the n-th-order nonlinear component.
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