Improved detection of echo signals from inside bone

The purpose of the study was to obtain useful information for diagnosing internal abnormalities of bones by ultrasound. We fabricated a transmitting and receiving system mainly targeting the bone and an image processing system using a computer, and studied the attenuation of ultrasound in animal bone (in vitro). The average value was about 37 dB. The examination was able to determine successfully the proper dynamic range for detection, and a B-mode image of the inside of the bone could be displayed. Here we describe a new transmitting and receiving system developed to improve the detection of echo signals from inside bones. In this method, two kinds of high sensitivity transducer were made as follows: (1) 5 HMz frequency, 6.5 mm diameter; (2) 10 HMz frequency, 13 mm diameter. By using this method, detectability of the echo signals can be increased more than with the former system. The results showed that the structure of the bones could be clearly seen in the B-mode images.