Ultrasonic fan beam scanner for computerized time-of-flight tomography

摘要

A fast ultrasonic scanner for soft tissue imaging and/or characterization has a transmitter with a divergent beam pattern and an arcuate array of receivers. The propagation delay time of a short acoustic pulse traversing a water bath and immersed specimen depends on the velocity distribution and is detected at each receiver. Digital data is derived from the receiver signals at many angular positions of the scan apparatus and is used to compute a reconstruction of the velocity distribution in the specimen. The instrument provides quantitative measurements of bulk tissue and has application in breast examination and mass screening for breast cancer.