A theoretical study of inertial cavitation from acoustic radiation force impulse imaging and implications for the mechanical index.
A theoretical study of inertial cavitation from acoustic radiation force impulse imaging and implications for the mechanical index.
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DOI：
10.1016/j.ultrasmedbio.2014.09.012
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发表时间：
2015-02
影响因子：
2.9
通讯作者：
Nightingale, Kathryn
中科院分区：
文献类型：
--
作者：
Church, Charles C.;Labuda, Cecille;Nightingale, Kathryn
关键词：
机械指数（MI）试图量化暴露于诊断超声将通过非热机制产生不良生物效应的可能性。MI的当前公式隐含地假设使用适合于B模式成像的短脉冲持续时间生成声场。然而，声辐射力脉冲（ARFI）成像采用高强度脉冲长达几百个声学周期。在水、尿、血液、心脏和骨骼肌、脑、肾、肝和皮肤中计算研究了增加脉冲持续时间对惯性空化阈值的影响。结果表明，虽然脉冲持续时间对三种液体中的空化阈值的影响可以是相当大的，但是通过例如，6% - 24%，在1 MHz时，对组织的影响较小。更重要的是，MI的频率依赖性似乎是不必要的保守，即，频率指数的大小可以增加到0.75。这些理论结果与实验测量的比较表明，一些组织不包含预先存在的，最佳尺寸的气泡假设为MI。这意味着在这些组织中，MI不一定是不良生物学效应概率的强预测因子。
The mechanical index (MI) attempts to quantify the likelihood that exposure to diagnostic ultrasound will produce an adverse biological effect by a nonthermal mechanism. The current formulation of the MI implicitly assumes that the acoustic field is generated using the short pulse durations appropriate to B-mode imaging. However, acoustic radiation force impulse (ARFI) imaging employs high-intensity pulses up to several hundred acoustic periods long. The effect of increased pulse durations on the thresholds for inertial cavitation was studied computationally in water, urine, blood, cardiac and skeletal muscle, brain, kidney, liver and skin. The results show that while the effect of pulse duration on cavitation thresholds in the three liquids can be considerable, reducing them by, e.g., 6% – 24% at 1 MHz, the effect in tissue is minor. More importantly, the frequency dependence of the MI appears to be unnecessarily conservative, i.e., that the magnitude of the exponent on frequency could be increased to 0.75. Comparison of these theoretical results with experimental measurements suggests that some tissues do not contain the pre-existing, optimally sized bubbles assumed for the MI. This means that in these tissues the MI is not necessarily a strong predictor of the probability for an adverse biological effect.
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影响因子：
2.4
作者：
Fuster, Daniel;Hauke, Guillermo;Dopazo, Cesar
通讯作者：
Dopazo, Cesar
DOI：
10.1109/58.585208
发表时间：
1997-01-01
影响因子：
3.6
作者：
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通讯作者：
Christopher, T
影响因子：
2.4
作者：
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通讯作者：
HERZFELD, KF
影响因子：
2.9
作者：
Church, CC
通讯作者：
Church, CC
影响因子：
2.9
作者：
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通讯作者：
Crum, Lawrence A.