Safety Assessment of Advanced Imaging Sequences II: Simulations
Safety Assessment of Advanced Imaging Sequences II: Simulations
复制标题
高级成像序列的安全评估 II：模拟
DOI：
10.1109/tuffc.2015.2499776
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
J. A. Jensen
中科院分区：
文献类型：
--
作者：
J. A. Jensen
提出了一种用于模拟高级超声成像序列的发射压力、强度和机械指数（MI）的自动方法。它基于使用Field II的压力场线性模拟，并且假设线性模拟可以达到FDA要求的预测MI和Ispta.3所需的准确度。该方法进行四种不同的成像方案，并进行比较，使用SARUS实验扫描仪进行测量。该序列包括具有F数为2的聚焦发射，具有产生高度非线性场的64个元素。每个发射点和成像点的模拟时间在0.67到2.8 ms之间，因此可以在不到1 s的时间内模拟单个空间位置的复杂发射序列。当使用从独立测量估计的探头脉冲响应时，线性模拟产生的MI的相对准确度在-12.1%至52.3%之间，Ispta.3的相对准确度在-38.6%至62.6%之间。当使用在单个点测量的压力响应来缩放模拟时，MI的准确度增加到-22%至24.5%之间，Ispta.3的准确度增加到-33.2%至27.0%之间。MI和Ita.3的空间分布与测量的空间分布紧密匹配，因此，可以使用模拟来选择用于测量强度的区域，从而显著减少测量时间。它可以通过显示发射压力场、焦点位置和强度分布的对称性来验证发射序列。
An automatic approach for simulating the emitted pressure, intensity, and mechanical index (MI) of advanced ultrasound imaging sequences is presented. It is based on a linear simulation of pressure fields using Field II, and it is hypothesized that linear simulation can attain the needed accuracy for predicting MI and Ispta.3 as required by FDA. The method is performed on four different imaging schemes and compared to measurements conducted using the SARUS experimental scanner. The sequences include focused emissions with an F-number of 2 with 64 elements that generate highly nonlinear fields. The simulation time is between 0.67 and 2.8 ms per emission and imaging point, making it possible to simulate even complex emission sequences in less than 1 s for a single spatial position. The linear simulations yield a relative accuracy on MI between -12.1% and 52.3% and for Ispta.3 between -38.6% and 62.6%, when using the impulse response of the probe estimated from an independent measurement. The accuracy is increased to between -22% and 24.5% for MI and between -33.2% and 27.0% for Ispta.3, when using the pressure response measured at a single point to scale the simulation. The spatial distribution of MI and Ita.3 closely matches that for the measurement, and simulations can, therefore, be used to select the region for measuring the intensities, resulting in a significant reduction in measurement time. It can validate emission sequences by showing symmetry of emitted pressure fields, focal position, and intensity distribution.