Goodwill Patrick W, Scott Greig C, Stang Pascal P, Conolly Steven M
UCSF/UC Berkeley Joint Graduate Group in Bioengineering, University of California, Berkeley, CA 94720, USA.
IEEE Trans Med Imaging. 2009 Aug;28(8):1231-7. doi: 10.1109/TMI.2009.2013849. Epub 2009 Feb 10.
The magnetic particle imaging (MPI) method directly images the magnetization of super-paramagnetic iron oxide (SPIO) nanoparticles, which are contrast agents commonly used in magnetic resonance imaging (MRI). MPI, as originally envisioned, requires a high-bandwidth receiver coil and preamplifier, which are difficult to optimally noise match. This paper introduces Narrowband MPI, which dramatically reduces bandwidth requirements and increases the signal-to-noise ratio for a fixed specific absorption rate. We employ a two-tone excitation (called intermodulation) that can be tailored for a high-Q, narrowband receiver coil. We then demonstrate a new MPI instrument capable of full 3-D tomographic imaging of SPIO particles by imaging acrylic and tissue phantoms.
磁粒子成像（MPI）方法直接对超顺磁性氧化铁（SPIO）纳米颗粒的磁化进行成像，这些纳米颗粒是磁共振成像（MRI）中常用的造影剂。最初设想的MPI需要一个高带宽接收线圈和前置放大器，而这两者很难实现最佳的噪声匹配。本文介绍了窄带MPI，它显著降低了带宽要求，并在固定的比吸收率下提高了信噪比。我们采用了一种双音激励（称为互调），它可以针对高Q值窄带接收线圈进行定制。然后，我们通过对丙烯酸和组织模型成像，展示了一种能够对SPIO颗粒进行全三维断层成像的新型MPI仪器。
