ULTRASONIC ENHANCED-CONTRAST IMAGER AND ITS METHOD

摘要

Considering that the frequency of the response signal from a contrast medium is distributed over a wide frequency range and the strength of the response signal is great, an ultrasonic enhanced-contrast imager is provided with a bandpass filter (34) for extracting a specific frequency component from a response signal received when an ultrasonic wave is radiated to an organism tissue containing a contrast medium. The imager is further provided with a means for limiting the bandwidth to a range from 1.2 f0 to 1.8 f0, not limiting it to the second harmonic 2f0 like in the prior art and a means for adding/subtracting the response signal obtained by applying a beam of ultrasonic wave of a first transmission waveform in a direction to/from the response signal obtained by applying in the same direction a beam of ultrasonic wave of a second transmission waveform the amplitude and frequency of which are modulated differently from those of the first transmission waveform. The response signal from the organic tissue can be discriminated from the second harmonic component contained in the response signal, and thereby the distribution of the contrast medium is clearly shown in the image.