We introduce a Magnetic Particle Imaging Susceptometer (MPIS) that uses a high-sensitivity atomic magnetometer (AM) for recording the spatial distribution of fluid-suspended magnetic nanoparticles. We have evaluated the MPIS performance by one-dimensional scans of structured nanoparticle phantoms, demonstrating, in particular, resolutions of ≈2:5 mm prior to deconvolution and «1 mm after deconvolution. Our instrument conceptually follows the general principle of Magnetic Particle Imaging (MPI) for encoding spatial distributions into magnetic flux density variations. Conversely to previously demonstrated MPI methods, MPIS works in time-space by recording time series of the sample's magnetic response including all Fourier components. The device deploys a specifically designed system of coils, a low-frequency excitation scheme, and a simple source localization algorithm. The difference of the AM's frequency response with respect to the conventional receive coil detection allows us to work at much lower driving frequencies. We demonstrate operation at frequencies on the order of 100 Hz, enabling the beneficial use of larger nanoparticles. The spatial distribution encoded into the particles' susceptibility needs a much lower excitation field amplitude compared to conventional MPI scanners. These two features make MPIS least harmful for biological samples and subjects compared to conventional MPI scanners. We also address performance characteristics and other possible applications of MPIS.

中文翻译：

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通过基于原子磁力计的磁纳法对磁性纳米颗粒分布进行成像。

我们介绍了一种磁粒子成像感受器（MPIS），它使用高灵敏度原子磁力计（AM）来记录流体悬浮的磁性纳米颗粒的空间分布。我们通过结构化纳米粒子模型的一维扫描评估了 MPIS 性能，特别证明了解卷积之前的分辨率为 ≈2:5 mm，解卷积后的分辨率为 «1 mm。我们的仪器在概念上遵循磁粒子成像 (MPI) 的一般原理，将空间分布编码为磁通密度变化。与之前演示的 MPI 方法相反，MPIS 通过记录样本磁响应（包括所有傅里叶分量）的时间序列在时空中工作。该设备部署了专门设计的线圈系统、低频激励方案和简单的源定位算法。AM 的频率响应与传统接收线圈检测的差异使我们能够在低得多的驱动频率下工作。我们演示了在 100 Hz 数量级的频率下运行，从而能够有益地使用较大的纳米粒子。与传统 MPI 扫描仪相比，编码到粒子磁化率中的空间分布需要低得多的激励场振幅。与传统 MPI 扫描仪相比，这两个功能使得 MPIS 对生物样本和受试者的危害最小。我们还讨论 MPIS 的性能特征和其他可能的应用。