Tracer design for magnetic particle imaging (invited)
Tracer design for magnetic particle imaging (invited)
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DOI：
10.1063/1.3676053
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发表时间：
2012-04-01
影响因子：
3.2
通讯作者：
Krishnan, Kannan M.
中科院分区：
文献类型：
--
作者：
Ferguson, R. Matthew;Khandhar, Amit P.;Krishnan, Kannan M.
磁性粒子成像（MPI）使用安全的氧化铁纳米粒子示踪剂，为医学成像提供了全新的功能，可用于血管成像和超灵敏癌症治疗。MPI可能是第一个本质上利用纳米材料特性的医学成像平台。MPI示踪剂含有磁性纳米颗粒，其可调的，尺寸依赖的磁性可以通过选择特定的颗粒尺寸和窄的尺寸分布来优化。在本文中，我们提出了实验MPI测量获得使用自制的MPI磁强计：零维MPI成像系统，旨在通过测量随时间变化的示踪剂磁化，M '（H（t）），在25 kHz的驱动频率的导数来表征示踪剂的性能。我们表明，MPI性能是通过选择相纯磁铁矿示踪剂的特定尺寸和窄的尺寸分布进行优化;在这项工作中，示踪剂与20 nm的中值直径，对数正态分布的形状参数，西格玛（v），等于0.26，流体动力学直径等于30 nm表现出最佳的性能。此外，这些优化的MPI示踪剂显示4倍更大的信号强度（在三次谐波测量）和20%更好的空间分辨率相比，商业纳米粒子开发的MRI。(C)2012年美国物理学会。[doi：10.1063/1.3676053]
Magnetic particle imaging (MPI) uses safe iron oxide nanoparticle tracers to offer fundamentally new capabilities for medical imaging, in applications as vascular imaging and ultra-sensitive cancer therapeutics. MPI is perhaps the first medical imaging platform to intrinsically exploit nanoscale material properties. MPI tracers contain magnetic nanoparticles whose tunable, size-dependent magnetic properties can be optimized by selecting a particular particle size and narrow size-distribution. In this paper we present experimental MPI measurements acquired using a homemade MPI magnetometer: a zero-dimensional MPI imaging system designed to characterize tracer performance by measuring the derivative of the time-varying tracer magnetization, M'(H(t)), at a driving frequency of 25 kHz. We show that MPI performance is optimized by selecting phase-pure magnetite tracers of a particular size and narrow size distribution; in this work, tracers with 20 nm median diameter, log-normal distribution shape parameter, sigma(v), equal to 0.26, and hydrodynamic diameter equal to 30 nm showed the best performance. Furthermore, these optimized MPI tracers show 4 x greater signal intensity (measured at the third harmonic) and 20% better spatial resolution compared with commercial nanoparticles developed for MRI. (C) 2012 American Institute of Physics. [doi: 10.1063/1.3676053]