VHF ultrasonic attenuation in mammalian tissue

Abstract

The ultrasonic attenuation has been determined in mammalian kidney tissue at 100 and 220 MHz. The attenuation, which is known to exhibit a linear dependence between 0.3 and 10 MHz, continues to be linear to about 100 MHz after which a square law {,or greater) dependence appears to exist. Subject Classification: 16.2.

Ultrasonic tissue characterization II

“…Using the shortterm data given in fig ures 7 [5][6] THRESHOLD FOR MODERATELY DARK|_ OBJECTS [9] REPLICATE POSSIBLE [48] MICROCYTES [49- series.…”

“…Reports of measurements of the longitudinal speed of sound in bone are largely in agreement that it is approximately twice that of soft tissues [46,[48][49][50].…”

“…However, recent observations have called these values into question, and Adler and Cook [48] have obtained absorption measurements of 1.5 cm"^and 2.2 cm"^in freshly frozen dog tibia at room temperature at, respectively, 3 and 5 MHz.…”

“…Anisotropy of elastic properties and variations in density of bone present special problems for measurement and for interpretation of results [48][49][50].…”

Measurement of ultrasonic velocity in several biological tissues

“…The attenuation coefficient increases nearly linearly with frequency over the range of frequencies employed with clinical ultrasound. Additionally, data indicate that the dependence of the attenuation coefficient on frequency at frequencies substantially above the clinical range is greater than linear (Kessler 1973). These factors combine to make the measurements of the attenuation coefficient at 100 MHz of little direct value to the clinical application of ultrasound, though the importance indirectly through contributions to the understanding of attenuation, scattering arid absorption processes in tissue should be quite significant.…”