Method for nonlinear imaging of ultrasound contrast agents at high frequencies

摘要

High frequency (about 15MHz), for example, using a linear array transducer, to detect the sub-harmonic signal and the nonlinear fundamental signal from the microbubble contrast agent in the body tissue, and AC phases present invention, and / or I use an ultrasonic pulse firing of multiple amplitude. It can be shown that the non-linear propagation of ultrasound in tissue, the contrast to tissue ratio (CTR) is decreased with an increase in the ultrasonic frequency. However, rather, results in significantly higher signal strength, the use of subharmonic signals in addition to the nonlinear fundamental signal, overcomes the limitations of the nonlinear tissue propagation than the second harmonic of a conventional used in the low frequency . In addition, more than 20MHz, the desired frequency which is a combination of band-pass filtering of subharmonic frequency band, and provides the ability to switch between acquisition of the phase inversion of the alternating purely the method, the frequency To minimize the loss of CTR when to increase.