| 摘要 |
An improved scanning method and apparatus using ultrasonic imaging techniques, wherein microscopic bubbles present in a liquid are scanned and detected by measurement of the ultrasonic energy radiated from the bubbles at a frequency different from that transmitted (i.e. a harmonic) so that the position and/or flow of the bubble-containing liquid can be studied. This is applicable to study of a wide variety of materials, in which such a bubble-containing liquid can be introduced, but is especially applicable to the study of blood in the vascular system, especially in the micro-vasculature in tissue. By also measuring the Doppler shift of the harmonics, a measure of the speed of flow of the liquid can be obtained in addition to its position. |
