Two dimensional magnetic particle spectrometry
Two dimensional magnetic particle spectrometry
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DOI：
10.1088/1361-6560/aa5bcd
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发表时间：
2017-05-07
影响因子：
3.5
通讯作者：
Buzug, T. M.
中科院分区：
文献类型：
--
作者：
Graeser, M.;von Gladiss, A.;Buzug, T. M.
磁粒子光谱法（MPS）是一种优秀的和直接的方法来确定磁性纳米粒子对振荡磁场的响应。这种场应用于磁粒子成像（MPI）。然而，现有技术的MPS设备缺乏在MPI设备中存在的多维场序列中激发粒子的能力。特别是由李萨如序列引起的粒子行为不能仅用一个激发方向测量。本文提出了一种新的MPS，它具有两个激励方向，以克服这一限制。两个场线圈都可以驱动AC以及DC电流，从而能够仿真MPI设备内部任意空间位置的场序列。由于直流电流可以非常快地切换，该设备可以用作系统校准单元，并在很短的时间内获得系统矩阵。这些对于MPI图像重建是至关重要的。由于MPS提供的信噪比比实际成像设备高出约1000倍，因此粒子信号的时空分析更精确且更容易完成。本文提出了四个系统矩阵，并用已实现的多维MPS进行了测量。此外，给出了Lissajous，径向和螺旋轨迹的粒子信号的时空比较。
Magnetic particle spectrometry (MPS) is an excellent and straight forward method to determine the response of magnetic nanoparticles to an oscillating magnetic field. Such fields are applied in magnetic particle imaging (MPI). However, state of the art MPS devices lack the ability to excite particles in multidimensional field sequences that are present in MPI devices. Especially the particle behavior caused by Lissajous sequences cannot be measured with only one excitation direction. This work presents a new kind of MPS which features two excitation directions to overcome this limitation. Both field coils can drive AC as well as DC currents and are thereby able to emulate the field sequences for arbitrary spatial positions inside an MPI device. Since the DC currents can be switched very fast, the device can be used as system calibration unit and acquire system matrices in very short time. These are crucial for MPI image reconstruction. As the signal-to-noise-ratio provided by the MPS is approximately 1000 times higher than that of actual imaging devices, the time space analysis of particle signals is more precise and easier done. Four system matrices are presented in this paper which have been measured with the realized multidimensional MPS. Additionally, a time space comparison of the particle signal for Lissajous, radial and spiral trajectories is given.