Hynynen K
Ultrasound Med Biol. 1987 Feb;13(2):85-91. doi: 10.1016/0301-5629(87)90078-0.
The results of an experimental study quantifying the temperature elevation gains produced by nonlinear propagation of focussed ultrasound fields in dogs' thighs in vivo are presented. Also, the intensity dependence of power absorption from a focussed ultrasound field was studied. The absorbed power appeared to elevate above intensities of 150-250 W cm-2 at 1 MHz in vivo. Enhanced temperature elevations were demonstrated at the same intensity levels, with the size of the elevation increasing with intensity. This phenomenon was large enough to be useful during focussed ultrasound hyperthermia since the maximum temperature gain was about 2 degrees C when a 5 degrees C temperature elevation was induced in the tissue. Using multiple overlapping beams, this effect was further increased.
本文呈现了一项实验研究的结果，该研究对聚焦超声场在犬大腿体内非线性传播所产生的温度升高进行了量化。此外，还研究了聚焦超声场功率吸收的强度依赖性。在体内，1兆赫兹时，吸收功率似乎在强度高于150 - 250瓦/平方厘米时升高。在相同强度水平下证实了温度升高增强，且升高幅度随强度增加。这种现象在聚焦超声热疗中足够显著，因为当在组织中诱导5摄氏度的温度升高时，最大温度升高约为2摄氏度。使用多个重叠波束，这种效应进一步增强。
