Magnetic particle imaging: Introduction to imaging and hardware realization
Magnetic particle imaging: Introduction to imaging and hardware realization
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DOI：
10.1016/j.zemedi.2012.07.004
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发表时间：
2012-01-01
影响因子：
2
通讯作者：
Luedtke-Buzug, Kerstin
中科院分区：
文献类型：
--
作者：
Buzug, Thorsten M.;Bringout, Gael;Luedtke-Buzug, Kerstin
磁性粒子成像（MPI）是最近发明的断层成像方法，其定量测量基于磁性纳米粒子的示踪剂的空间分布。新的模式承诺高灵敏度和高空间以及时间分辨率。MPI在改善介入和图像引导外科手术方面具有很高的潜力，因为如今，已建立的医学成像模式通常仅在这些重要成像特性中的一个或两个方面表现出色。MPI利用磁性纳米颗粒的非线性磁化特性。为此，产生并叠加两个磁场，即静态选择场和振荡驱动场。如果超顺磁性氧化铁纳米颗粒（SPIO）经受振荡磁场，则颗粒将与非线性磁化响应反应，这可以用适当的拾取线圈布置来测量。由于粒子磁化的非线性，所接收的信号由基本激励频率以及谐波组成。在分离基波信号之后，可以基于谐波定量地重构纳米颗粒浓度。空间编码是通过静态选择场产生无场点来实现的，无场点通过驱动场在视场中移动，本文重点介绍了基于频率的图像重建方法和相应的成像设备，同时也介绍了x空间MPI和无场线成像等替代概念。在概述MPI扫描器的基础上，总结了其硬件实现的现状。
Magnetic Particle Imaging (MPI) is a recently invented tomographic imaging method that quantitatively measures the spatial distribution of a tracer based on magnetic nanoparticles. The new modality promises a high sensitivity and high spatial as well as temporal resolution. There is a high potential of MPI to improve interventional and image-guided surgical procedures because, today, established medical imaging modalities typically excel in only one or two of these important imaging properties. MPI makes use of the non-linear magnetization characteristics of the magnetic nanoparticles. For this purpose, two magnetic fields are created and superimposed, a static selection field and an oscillatory drive field. If superparamagnetic iron-oxide nanoparticles (SPIOs) are subjected to the oscillatory magnetic field, the particles will react with a non-linear magnetization response, which can be measured with an appropriate pick-up coil arrangement. Due to the non-linearity of the particle magnetization, the received signal consists of the fundamental excitation frequency as well as of harmonics. After separation of the fundamental signal, the nanoparticle concentration can be reconstructed quantitatively based on the harmonics. The spatial coding is realized with the static selection field that produces afield-free point, which is moved through the field of view by the drive fields.This article focuses on the frequency-based image reconstruction approach and the corresponding imaging devices while alternative concepts like x-space MPI and field-free line imaging are described as well. The status quo in hardware realization is summarized in an overview of MPI scanners.