Nathan Bliss, Utah Valley University
Health
High-frequency (HF) ultrasound in the 20-80 MHz range has recently been found to be sensitive to pathology in tissue margins from breast cancer surgery. In order to improve the resolution and sensitivity of this method, however, transducers need to be employed that have piezoelectric elements that are smaller than those currently in use. The purpose of this study was to determine if similar results can be obtained from small element transducers (Blatek pachyometer, 50 MHz, element diameter < 2 mm) as compared to large element immersion transducers (Olympus NDT, V358-SU, 50 MHz, 6.35-mm diameter active element). Ultrasonic tests were performed on 10 bovine heart specimens of varying surface structure (myocardium, endocardium, and epicardium). Pulse-echo and through transmission measurements using a HF square-wave pulser/receiver (UTEX, UT340) and a digital storage oscilloscope (Agilent, DSOX3104A, 1 GHz, 4 analog channels) were acquired from a total of 2 sites per bovine specimen, first testing all specimens with the large transducers then again with the small transducers. Specimens were marked with India ink for location and accuracy of testing. The density of peaks in the ultrasonic spectra of the large transducers paralleled those of small transducers. Results from HF ultrasonic measurements of bovine heart tissue obtained from large transducers compared to the small transducers indicate that they produce statistically comparable peak densities.