Numerical Experiments on the Contrast Capability of Magnetic Resonance Electrical Property Tomography
Numerical Experiments on the Contrast Capability of Magnetic Resonance Electrical Property Tomography
复制标题
磁共振电性能层析成像对比能力的数值实验
DOI：
10.2463/mrms.mp.2018-0167
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发表时间：
2019-04
影响因子：
3
通讯作者：
Xin Sherman Xuegang
中科院分区：
文献类型：
--
作者：
Duan Song;Zhu Yurong;Liu Feng;Xin Sherman Xuegang
目的：磁共振电性断层扫描（MR EPT）是一种无创获取生物组织电性（EP）分布的技术，在肿瘤的早期检测中具有广阔的应用前景。然而，该技术的对比能力（CC）尚未得到充分的研究。本工作旨在从理论上探讨CC检测EP值变化和成像区域大小的方法。方法：设计模拟方案，评估MR EPT的CC。仿真研究的优点是可以准确地得到磁场。利用基于B1+的不同信噪比齐次亥姆霍兹方程重构嵌入不同大小和EP靶区的幻体EP图。当靶区大小与拉普拉斯核相同时，确定最小可检测靶区对比度；当靶区对比度与大脑健康组织与恶性组织的差异相同时，确定最小可检测靶区大小，以此来估计CC。结果：使用无噪声的B1+，电导率和相对介电常数的最小可检测对比度σ和对比度εr分别为1%和3%，最小可检测目标区域尺寸为1网格单元（模拟中使用的基本单元尺寸）。随着B1+信噪比的增加，最小可检测EP对比度和靶区大小减小。结论：磁共振EPT的CC与磁场信噪比有关。在高信噪比的磁场中，较小的EP对比度和尺寸是检测所必需的。获得高信噪比的磁场对提高磁流变EPT的CC具有重要意义。
Purpose: Magnetic resonance electrical property tomography (MR EPT) is a technique for non-invasively obtaining the electric property (EP) distribution of biological tissues, with a promising potential for application in the early detection of tumors. However, the contrast capability (CC) of this technique has not been fully studied. This work aims to theoretically explore the CC for detecting the variation of EP values and the size of the imaging region. Methods: A simulation scheme was specifically designed to evaluate the CC of MR EPT. The simulation study has the advantage that the magnetic field can be accurately obtained. EP maps of the designed phantom embedded with target regions of designated various sizes and EPs were reconstructed using the homogeneous Helmholtz equation based on B1+ with different signal-to-noise ratios (SNRs). The CC was estimated by determining the smallest detectable EP contrast when the target region size was as large as the Laplacian kernel and the smallest detectable target region size when the EP contrast was the same as the difference between healthy and malignant tissues in the brain, based on the reconstructed EP maps. Results: Using noise free B1+, the smallest detectable contrastσ and contrastεr were 1% and 3%, respectively, and the smallest detectable target region size was 1 mesh unit (the base unit size used in the simulation) for conductivity and relative permittivity. The smallest detectable EP contrast and target region size were decreased as the B1+ SNR increased. Conclusion: The CC of MR EPT was related with the SNR of the magnetic field. A small EP contrast and size were necessary for detection at a high-SNR magnetic field. Obtaining a high-SNR magnetic field is important for improving the CC of MR EPT.
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影响因子：
--
作者：
Katscher U;Kim DH;Seo JK
通讯作者：
Seo JK
影响因子：
3.3
作者：
Stollberger, R;Wach, P
通讯作者：
Wach, P
影响因子：
3.3
作者：
Kim, Dong-Hyun;Choi, Narae;Gho, Sung-Min;Shin, Jaewook;Liu, Chunlei
通讯作者：
Liu, Chunlei
基于磁共振的电特性断层扫描中随机噪声限制信噪比的理论研究
影响因子：
10.6
作者：
Lee SK;Bulumulla S;Hancu I
通讯作者：
Hancu I
影响因子：
3.3
作者：
Jinghua Wang;M. Qiu;Qing Yang;Michael B. Smith;R. Constable
通讯作者：
Jinghua Wang;M. Qiu;Qing Yang;Michael B. Smith;R. Constable