Pulse Inversion Techniques in Ultrasonic Nonlinear Imaging

Pulse inversion (PI) technique plays an important role in ultrasonic nonlinear imaging. For tissue imaging, PI technique provides suppression of spectral leakage and, thus, produces better image contrast. For contrast imaging, contrast between the agents and surrounding tissues are also enhanced with this technique by distinguishing nonlinear microbubbles from the background in either Doppler domain or radiofrequency domain. This paper reviews the theoretical backgrounds and relevant issues of the PI technique. Improvements in image contrast with the PI technique in both tissue harmonic imaging and contrast harmonic imaging are discussed in detail. In addition, potential motion artifacts and related contrast degradation are also included.