PROPERTIES OF PHANTOM TISSUELIKE POLYMETHYLPENTENE IN THE FREQUENCY RANGE 20-70 MHZ
PROPERTIES OF PHANTOM TISSUELIKE POLYMETHYLPENTENE IN THE FREQUENCY RANGE 20-70 MHZ
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DOI：
10.1016/j.ultrasmedbio.2011.05.023
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发表时间：
2011-08-01
影响因子：
2.9
通讯作者：
Mehi, James
中科院分区：
文献类型：
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作者：
Madsen, Ernest L.;Deaner, Meagan E.;Mehi, James
定量超声（QUS）已被用于在普通腹部超声频率（2至15 MHz）下表征软组织，并开始在高频（20至70 MHz）下应用。例如，可以使用参考模体在体内估计后向散射和衰减系数。在高频率下，混响不影响测量是至关重要的。这种混响可以发生在幻影的扫描窗口和换能器组件之间，也可以发生在其表面之间的扫描窗口内。换能器被设计成最小化换能器和软组织之间的混响。因此，伪影扫描窗口的声阻抗应该是类似于组织的；聚甲基戊烯（TPX）因其具有类似组织的声阻抗而被广泛使用。对于QUS来说，对扫描窗透射系数的校正也是至关重要的。计算后者需要了解超声波的特性，即密度、速度和衰减系数。这项工作报告了两种版本的TPX在高频范围内的超声特性值。其中一种形式（TPX薄膜）用作高频幻影的扫描窗口，在40 MHz和22℃下，衰减系数为120 dB/cm，传播速度为2093 m/s。（E-mail: elmadsen@wisc.edu） (C) 2011年世界超声医学与生物学联合会。
Quantitative ultrasound (QUS) has been used to characterize soft tissues at ordinary abdominal ultrasound frequencies (2 to 15 MHz) and is beginning application at high frequencies (20 to 70 MHz). For example, backscatter and attenuation coefficients can be estimated in vivo using a reference phantom. At high frequencies, it is crucial that reverberations do not compromise the measurements. Such reverberations can occur between the phantom's scanning window and transducer components as well as within the scanning window between its surfaces. Transducers are designed to minimize reverberations between the transducer and soft tissue. Thus, the acoustic impedance of a phantom scanning window should be tissuelike; polymethylpentene (TPX) is commonly used because of its tissuelike acoustic impedance. For QUS, it is also crucial to correct for the transmission coefficient of the scanning window. Computation of the latter requires knowledge of the ultrasonic properties, viz, density, speed and attenuation coefficients. This work reports values for the ultrasonic properties of two versions of TPX over the high-frequency range. One form (TPX film) is used as a scanning window on high-frequency phantoms, and at 40 MHz and 22 degrees C was found to have an attenuation coefficient of 120 dB/cm and a propagation speed of 2093 m/s. (E-mail: elmadsen@wisc.edu) (C) 2011 World Federation for Ultrasound in Medicine & Biology.