Hachiya H, Ohtsuki S, Tanaka M, Dunn F
Precision and Intelligence Laboratory, Tokyo Institute of Technology, Yokohama, Japan.
J Acoust Soc Am. 1992 Sep;92(3):1564-8. doi: 10.1121/1.403897.
The sound speed in biological tissues provides important diagnostic and treatment planning information. Conventional methods of sound-speed determination generally require that transducers make physical contact with specimens in order to measure thickness and travel time in the time domain. The physical contact may cause deformation and affect blood flow and the measurement of travel time in the time domain may be sensitive to waveform distortion due to tissue inhomogeneity and surface roughness. A method for determination of the sound speed is proposed in which the sound travel time in the sample and the difference in total travel time from the transducer to the rigid reflector due to the presence of the sample are estimated in the frequency domain and which does not require physical contact of ultrasonic probes to living or freshly excised tissue specimens. Ultrasonic speed measurements in silicone rubber and acrylic resin specimens verified the method validity. The standard deviation of the measurements over a 10- x 10-mm area is less than 4 m/s. Sound-speed distribution measurements of porcine muscle are in agreement with previously published results.
生物组织中的声速提供了重要的诊断和治疗计划信息。传统的声速测定方法通常要求换能器与样本进行物理接触，以便在时域中测量厚度和传播时间。这种物理接触可能会导致样本变形并影响血流，并且在时域中传播时间的测量可能对由于组织不均匀性和表面粗糙度引起的波形失真敏感。本文提出了一种声速测定方法，该方法在频域中估计样本中的声传播时间以及由于样本的存在而导致的从换能器到刚性反射器的总传播时间的差异，并且不需要超声探头与活体或新鲜切除的组织样本进行物理接触。在硅橡胶和丙烯酸树脂样本中进行的超声速度测量验证了该方法的有效性。在10×10毫米区域上测量的标准偏差小于4米/秒。猪肌肉的声速分布测量结果与先前发表的结果一致。
