Them Kolja, Kaul M G, Jung C, Hofmann M, Mummert T, Werner Franziska, Knopp Tobias
IEEE Trans Med Imaging. 2016 Mar;35(3):893-900. doi: 10.1109/TMI.2015.2501462. Epub 2015 Nov 20.
Biomedical applications such as cell tracking and angiography require the detection of low concentrations of superparamagnetic iron oxide nanoparticles (SPIOs) for imaging purposes. Magnetic particle imaging (MPI) is a new technology which enables the quantitative and time-resolved localization of SPIO distributions. However, the minimum concentration at which the SPIOs can be reconstructed with a suitable quality still remains to be investigated. In this work we examine the background signals in raw data that were measured without any SPIOs in the scanner tube. We show that a background subtraction in combination with a frequency cutoff for the dynamic part of the background signal lowers the detection limit for SPIOs in MPI up to a factor of ten. In-vivo mouse experiments show that for early time points from when the tracer enters the vena cava a reconstructed image of sufficient quality can only be obtained when a background subtraction is performed.
诸如细胞追踪和血管造影等生物医学应用需要检测低浓度的超顺磁性氧化铁纳米颗粒（SPIO）以用于成像目的。磁粒子成像（MPI）是一项新技术，它能够对SPIO分布进行定量和时间分辨定位。然而，能够以合适质量重建SPIO的最低浓度仍有待研究。在这项工作中，我们检查了在扫描管中未添加任何SPIO时测量的原始数据中的背景信号。我们表明，背景减法与背景信号动态部分的频率截止相结合，可将MPI中SPIO的检测限降低至十分之一。体内小鼠实验表明，在示踪剂进入腔静脉后的早期时间点，只有进行背景减法才能获得质量足够的重建图像。
