| 摘要 |
PURPOSE:To detect the difference between the elastic properties in a scattering body, by a method wherein pressure change is given to an object to be examined and an ultrasonic wave is allowed to be incident to the object to be examined to receive the reflected wave in said body and the change of a receiving signal is detected. CONSTITUTION:When low frequency vibration is applied to the surface of a specimen 1 by a vibration plate 2, said vibration propagates through the specimen and a large number of minute reflecting bodies in the specimen receive perturbation by the propagating vibration pressure. Difference is generated in the response to an ultrasonic wave between a perturbation receiving case and a no perturbation receiving case. Since the timings of two envelope waves are determined so that the displacement of low frequency vibration becomes a different phase, a change rate DELTAE shows an elastic property being the easiness to receive the perturbation in the specimen 1. Therefore, the distribution image of the elastic properties in the specimen 1 is displayed on a display apparatus 85 as a tomographic image. By this method, the difference between the elastic properties unclear in a boundary within a relatively soft scattering body is detected with high sensitivity and the distribution of internal elastic properties can be displayed as an image. |
