Single Magnetic Particle Motion in Magnetomotive Ultrasound: An Analytical Model and Experimental Validation.
Single Magnetic Particle Motion in Magnetomotive Ultrasound: An Analytical Model and Experimental Validation.
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DOI：
10.1109/tuffc.2021.3072867
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发表时间：
2021-08
期刊：
影响因子：
--
通讯作者：
Oldenburg AL
中科院分区：
文献类型：
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作者：
Levy BE;Oldenburg AL
磁动力超声 (MMUS) 是一种新兴的成像方式，其中磁性纳米粒子 (MNP) 用作造影剂。 MNP 由时变磁力驱动，并通过信号处理算法检测由此产生的周围组织的运动。然而，目前还没有分析模型可以定量预测这种磁致位移。为了预测 MNP 分布上的力引起的运动，在这项工作中，提出并验证了一个模型，该模型最初源自纳维-斯托克斯方程，用于单个磁性粒子在磁梯度力作用下的运动。测量空间不均匀和时间正弦力的位移幅度作为力幅度和杨氏模量的函数，并且预测的线性和逆关系分别在明胶模型中得到证实，4 个数据集中有 3 个表现出 R2 ≥ 0.88。预测位移幅度与实验结果之间的平均绝对不确定度为 14%。这些发现提供了一种方法，可以预测 MMUS 系统的性能，以验证系统是否在理论极限范围内工作，并比较各个实验室的结果。
Magnetomotive Ultrasound (MMUS) is an emerging imaging modality in which magnetic nanoparticles (MNPs) are used as contrast agents. MNPs are driven by a time-varying magnetic force, and the resulting movement of the surrounding tissue is detected with a signal processing algorithm. However, there is currently no analytical model to quantitatively predict this magnetically-induced displacement. Toward the goal of predicting motion due to forces on a distribution of MNPs, in this work a model originally derived from the Navier-Stokes equation for the motion of a single magnetic particle subject to a magnetic gradient force is presented and validated. Displacement amplitudes for a spatially inhomogeneous and temporally sinusoidal force were measured as a function of force amplitude and Young’s modulus, and the predicted linear and inverse relationships were confirmed in gelatin phantoms respectively with 3 out of 4 datasets exhibiting R2 ≥ 0.88. The mean absolute uncertainty between the predicted displacement magnitude and experimental results was 14%. These findings provide a means by which the performance of MMUS systems may be predicted to verify that systems are working to theoretical limits, and to compare results across laboratories.