Laboratory of Ultrasonic Electronics, Doshisha University, Kyoto, Japan.
Ultrasound Med Biol. 2011 Nov;37(11):1923-9. doi: 10.1016/j.ultrasmedbio.2011.08.005. Epub 2011 Oct 2.
We investigated the properties of ultrasonic waves in bovine bone marrow. Six bone marrow samples were obtained from different parts (proximal, middle and distal) of the shafts of two bovine femora without destruction. The measured frequency range was 3 to 10 MHz, and the temperature range was 15 to 40°C. Both wave velocity and attenuation coefficient in bone marrow always decreased as temperature increased. The velocity ranged from 1400 to 1610 m/s and attenuation coefficient ranged from 4 to 16 dB/cm. Wave velocities in bone marrow were similar to those in water, whereas the temperature dependences were different, and the wave attenuation coefficients were much higher than those in water. The dependence of velocity on temperature changed slightly around 23-24°C, where a transition from soft gel to oily liquid occurred. The transition temperature was confirmed by differential scanning calorimetry (DSC). Below this transition temperature, positive velocity dispersion was observed.
我们研究了牛骨髓中超声波的特性。从两个牛股骨的干骺端（近端、中部和远端）不同部位获得了 6 个骨髓样本，未破坏样本。测量的频率范围为 3 到 10 MHz，温度范围为 15 到 40°C。随着温度的升高，骨髓中的波速和衰减系数总是降低。速度范围从 1400 到 1610 m/s，衰减系数范围从 4 到 16 dB/cm。骨髓中的波速与水中的波速相似，但温度依赖性不同，波衰减系数比水中的高得多。速度对温度的依赖性在 23-24°C 左右变化不大，在此温度下发生了从软凝胶到油性液体的转变。通过差示扫描量热法（DSC）证实了转变温度。低于此转变温度，观察到正速度弥散。
