Optimization of Magnetic Nanoparticles for Magnetic Particle Imaging
Optimization of Magnetic Nanoparticles for Magnetic Particle Imaging
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DOI：
10.1109/tmag.2012.2197601
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发表时间：
2012-11-01
影响因子：
2.1
通讯作者：
Schilling, Meinhard
中科院分区：
文献类型：
--
作者：
Ludwig, Frank;Wawrzik, Thilo;Schilling, Meinhard
对 FeraSpin R 和 FeraSpin 系列磁性纳米颗粒的磁性及其作为磁性颗粒成像示踪剂的适用性进行了系统研究。磁粉光谱测量表明，FeraSpin R 表现出与 Resovist 非常相似的谐波频谱，而 FeraSpin L、XL 和 XXL 与 FeraSpin R 相比，谐波幅度增加了 2.5 倍。为了了解 FeraSpin 系列不同样品之间的差异（代表从 FeraSpin R 中提取的相同成分的尺寸选定的窄分布颗粒）、交流磁化率 (ACS) 测量、磁松弛测量(MRX) 和静态 M-H 曲线对悬浮和固定颗粒样品进行分析。对固定样品的 ACS 和 MRX 测量表明，尽管流体动力学尺寸分布狭窄，但各向异性能量分布广泛。静态磁化测量表明，所有样品都表现出磁矩的双峰分布：较大磁矩的分数对应于整个颗粒核心的贡献，而较小的磁矩则归因于构成核心的微晶的贡献。
Systematic studies of the magnetic properties of magnetic nanoparticles from FeraSpin R and the FeraSpin Series with respect to their suitability as tracers for magnetic particle imaging are presented. Magnetic particle spectroscopy measurements indicate that FeraSpin R exhibits a harmonic spectrum very similar to that of Resovist, whereas FeraSpin L, XL, and XXL show a 2.5-fold increase of harmonic amplitudes compared to FeraSpin R. To understand the differences between the various samples of the FeraSpin Series, representing size-selected, narrowly distributed particles of identical composition extracted from FeraSpin R, measurements of the ac susceptibility (ACS), magnetorelaxometry (MRX), and static M - H curves were performed on suspended and immobilized particle samples. ACS and MRX measurements on immobilized samples indicate a wide distribution of anisotropy energies despite the narrow distribution of hydrodynamic sizes. Static magnetization measurements show that all samples exhibit a bimodal distribution of magnetic moments: The fraction of larger moments corresponds to the contribution from the overall particle core, whereas the smaller is attributed to the contribution from the crystallites comprising the core.