Method for discriminating speckle noises from signals in ultrasonic tomography apparatus and ultrasonic tomography apparatus including speckle noise removing circuit

摘要

A discrimination method of speckle noises in an ultrasonic tomography apparatus, includes a step of scanning a predetermined area of an object to be examined by an ultrasonic wave and receiving an ultrasonic echo signal from the object, a step of producing a digital echo signal on the basis of the ultrasonic echo signal to store it in a memory unit, a step of reading out the echo signals of a plurality of fields obtained by a plurality of continuous scanning operations from the memory unit, a step of statistically processing the echo signals at the same pixel position of the plurality of fields to obtain a judgment value and a step of comparing the judgment value with a predetermined reference value to decide in accordance with the compared result whether the echo signals of the statistically processed pixel contain speckle noises or not. An ultrasonic tomography apparatus in which a predetermined area of an object to be examined is scanned with an ultrasonic wave by means of a probe to receive an ultrasonic echo signal from the object so that a tomographic image of the object is produced from the received ultrasonic echo signal, includes a signal processing unit for producing a digital echo signal on the basis of the ultrasonic echo signal and storing the digital echo signal.