Investigation of particle mobility in Magnetic Particle Imaging (MPI)

磁粒子成像 (MPI) 中粒子迁移率的研究

• 批准号: 283337281
• 负责人: Professor Dr. Meinhard Schilling
• 金额: --
• 依托单位: Institut für Elektrische Messtechnik und Grundlagen der Elektrotechnik
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/283337281?language=en
• 关键词: Investigation; particle; mobility; Magnetic; Particle

The project aims for the quantification of the particle mobility in MPS/MPI with the help of defined particle-matrix-systems. Particle mobility is defined via the Brownian time constant and covers the viscosity of the medium and the hydrodynamic volume of the particles. By analyzing interactions and modelling of the signal generation process in MPS/MPI, particle mobility can be deducted from the measured particle signal. The results can be transferred into the imaging system allowing a spatially and timely resolved analysis of the particle-matrix-system (approx. 1 mm resolution and 1 Hz imaging rate). Imaging of the particle mobility considering particle-matrix-interactions is of great importance for numerous biomedical and technological applications. In the project context various particle-matrix-systems (including commercial particles as well as particles from partners in the SPP1681) are to be analyzed. The viscosity of the medium provides a tunable parameter, so that viscous particle-matrix-systems serve as a reference system for particle mobility studies. The degree of determination for viscosity estimation in MPS/MPI can be verified through rheological reference measurements. For the estimation of viscosity from MPS data a calibration-based approach is considered, which requires a viscosity series to be measured and evaluated. Furthermore, we seek to model the viscosity contribution in the MPS signal, which draws a direct connection between the particle mobility and the measurement signal. Applicability of the derived methods for mobility estimation in MPS will be tested against biological particle-matrix-systems, i.e. plasma, cells, tissue. From viscosity studies in MPS, the methods and models will be adopted for Magnetic Particle Imaging. Mobility-aware MPI imaging constitutes an important step towards functional imaging in MPI, where the local nano-/micro-viscosity in a voxel is imaged supplementary to the spatial concentration distribution of the magnetic nanoparticle tracer. The relation between a voxel-averaged macroscopic viscosity and the local mobility of the tracer is of great interest and can be dealt with collectively within the framework of the SPP1681. In practical application scenarios, i.e. in biological media, the quantifiable determination of particle concentration and particle mobility is complicated by non-Newtonian viscosity or viscoelasticity of the particle-matrix-system. A concluding analysis of viscoelastic particle systems and interactions in biological environments is projected.

该项目的目的是在定义的粒子矩阵系统的帮助下量化MPS/MPI中的粒子迁移率。颗粒迁移率通过布朗时间常数定义，并涵盖介质的粘度和颗粒的流体动力学体积。通过分析MPS/MPI中信号生成过程的相互作用和建模，可以从测量的颗粒信号中推导出颗粒迁移率。结果可以传输到成像系统中，从而允许对颗粒基质系统进行空间和时间分辨分析（约100%）。1 mm分辨率和1 Hz成像速率）。考虑颗粒-基质相互作用的颗粒迁移率成像对于许多生物医学和技术应用具有重要意义。在项目背景下，将分析各种颗粒基质系统（包括商业颗粒以及SPP 1681中合作伙伴的颗粒）。介质的粘度提供了一个可调的参数，使粘性颗粒基质系统作为一个参考系统的颗粒迁移率的研究。MPS/MPI中粘度估计的确定程度可通过流变参考测量进行验证。为了从MPS数据估计粘度，考虑基于校准的方法，其需要测量和评估粘度系列。此外，我们试图对MPS信号中的粘度贡献进行建模，这在颗粒迁移率和测量信号之间建立了直接联系。将针对生物颗粒-基质-系统（即血浆、细胞、组织）测试MPS中迁移率估计的衍生方法的适用性。从MPS中的粘度研究，方法和模型将被采用的磁性粒子成像。迁移率感知MPI成像构成了MPI中功能成像的重要一步，其中体素中的局部纳米/微米粘度被成像为磁性纳米颗粒示踪剂的空间浓度分布的补充。体素平均宏观粘度和示踪剂的局部流动性之间的关系是非常感兴趣的，并且可以在SPP 1681的框架内集体处理。在实际应用场景中，即在生物介质中，颗粒浓度和颗粒迁移率的可量化确定由于颗粒-基质系统的非牛顿粘度或粘弹性而变得复杂。粘弹性粒子系统和生物环境中的相互作用的总结分析。