Journal of Ultrasound in Medicine, Vol 20, Issue 5 473-480, Copyright © 2001 by American Institute of Ultrasound in Medicine
Attenuation coefficient and sound speed in human myometrium and uterine fibroid tumors
A. Keshavarzi, S. Vaezy, P. J. Kaczkowski, G. Keilman, R. Martin, E. Y. Chi, R. Garcia and V. Y. Fujimoto
Department of Bioengineering, University of Washington, Seattle 98195, USA.
OBJECTIVE: To develop a noninvasive method for treatment of uterine fibroid
tumors using high-intensity focused ultrasound. Optimal high-intensity
focused ultrasound treatment would be dependent on quantitative information
about ultrasonic tissue characteristics. METHODS: Ultrasonic attenuation
and the sound speed of fresh human fibroid tumors and myometrium were
measured as a function of frequency (1-3 MHz) by using a pulse transmission
technique before and after in vitro high-intensity focused ultrasound
treatment (3.5 MHz at an intensity of 2,000 W/cm2). RESULTS: The ranges of
the attenuation coefficients, before and after high-intensity focused
ultrasound treatment, were 0.9 to 2.2 and 1.8 to 3.9 dB/cm2, respectively,
for fibroid tumors and 0.5 to 1.6 and 1.7 to 3.3 dB/cm2, respectively, for
myometrium. Although the sound speed appeared to be independent of
frequency (1,611 to 1,616 m/s at 1 to 3 MHz) in both types of tissues, a
slight increase of approximately 4 to 14 m/s was observed after
high-intensity focused ultrasound treatment. CONCLUSIONS: The results of
this study represent our first reported values of the attenuation
coefficient and sound speed in fibroid tumors and myometrium before and
after high-intensity focused ultrasound treatment.
