Nonlinear Susceptibility Magnitude Imaging of Magnetic Nanoparticles.
Nonlinear Susceptibility Magnitude Imaging of Magnetic Nanoparticles.
复制标题
DOI：
10.1016/j.jmmm.2014.11.049
复制
发表时间：
2015-03-15
影响因子：
2.7
通讯作者：
Diamond SG
中科院分区：
文献类型：
--
作者：
Ficko BW;Giacometti P;Diamond SG
本研究展示了一种利用磁性纳米颗粒（mNPs）非线性磁化特性产生的空间信息来提高磁化率成像（SMI）分辨率的方法。在这个非线性SMI的概念验证研究中，一对驱动线圈和几个永磁体产生外加磁场，一个线圈用作磁场传感器。驱动线圈中的正弦交流电流（AC）导致mNP在初级频率下的线性磁化响应，而在谐波频率和互调频率下的非线性响应。利用线性和非线性相结合的数据重构体素数依次增加的层析图像，评估非线性响应的空间信息含量。仅使用线性数据是不可能用一对驱动线圈和单个传感器精确地重建超过2个体素的。然而，发现非线性SMI可以使用相同的物理配置准确地重建12个体素（R2 = 0.99, CNR = 84.9）。然后探讨了几种时间复用方法，以确定是否可以通过改变来自两个驱动线圈的外加磁场的幅度，相位和频率来获得额外的空间信息。异步相位调制、幅度调制、互调相位调制和频率调制均能精确重建6体素（R2 > 0.9），表明时间复用是进一步提高非线性SMI分辨率的有效方法。非线性mNP响应的空间信息含量和时间复用增强分辨率的潜力证明了非线性SMI的概念和优势。
This study demonstrates a method for improving the resolution of susceptibility magnitude imaging (SMI) using spatial information that arises from the nonlinear magnetization characteristics of magnetic nanoparticles (mNPs). In this proof-of-concept study of nonlinear SMI, a pair of drive coils and several permanent magnets generate applied magnetic fields and a coil is used as a magnetic field sensor. Sinusoidal alternating current (AC) in the drive coils results in linear mNP magnetization responses at primary frequencies, and nonlinear responses at harmonic frequencies and intermodulation frequencies. The spatial information content of the nonlinear responses is evaluated by reconstructing tomographic images with sequentially increasing voxel counts using the combined linear and nonlinear data. Using the linear data alone it is not possible to accurately reconstruct more than 2 voxels with a pair of drive coils and a single sensor. However, nonlinear SMI is found to accurately reconstruct 12 voxels (R2 = 0.99, CNR = 84.9) using the same physical configuration. Several time-multiplexing methods are then explored to determine if additional spatial information can be obtained by varying the amplitude, phase and frequency of the applied magnetic fields from the two drive coils. Asynchronous phase modulation, amplitude modulation, intermodulation phase modulation, and frequency modulation all resulted in accurate reconstruction of 6 voxels (R2 > 0.9) indicating that time multiplexing is a valid approach to further increase the resolution of nonlinear SMI. The spatial information content of nonlinear mNP responses and the potential for resolution enhancement with time multiplexing demonstrate the concept and advantages of nonlinear SMI.
登录
查看更多内容
影响因子：
3.4
作者：
Biederer, S.;Knopp, T.;Buzug, T. M.
通讯作者：
Buzug, T. M.
影响因子：
2.7
作者：
Ferguson RM;Minard KR;Krishnan KM
通讯作者：
Krishnan KM
DOI：
10.1088/1751-8113/43/1/012002
发表时间：
2010-01-08
影响因子：
2.1
作者：
Knopp, T.;Sattel, T. F.;Buzug, T. M.
通讯作者：
Buzug, T. M.
影响因子：
3.7
作者：
López-Ruiz, R;Luis, F;García-Palacios, JL
通讯作者：
García-Palacios, JL
影响因子：
2.1
作者：
Nakamura, Kosuke;Ueda, Koji;Takemura, Yasushi
通讯作者：
Takemura, Yasushi