Magnetic Particle Spectroscopy Enables Real-Time, Harmonic-Based Monitoring of Blood Coagulation Dynamics
Researchers demonstrated that magnetic particle spectroscopy, the analytical counterpart to magnetic particle imaging (MPI), can continuously monitor blood coagulation. Using the iron oxide tracer Resotran, harmonic signal decay correlated with clot formation, supporting real-time, radiation-free bedside coagulation assessment.
Magnetic particle imaging (MPI), a radiation-free imaging modality based on the nonlinear magnetic response of iron oxide nanoparticles, provides high sensitivity and real-time, quantitative, background-free imaging. With the clinical approval of the prescription medicine Resotran as an MPI-suitable tracer and the development of first human-scale scanners, clinical applications are within reach. Magnetic particle spectroscopy (MPS), the non-imaging counterpart of MPI, enables sensitive analytics by exploiting the signal response of magnetic nanoparticles. In a pilot study, researchers examined the possibilities of MPS for continuously monitoring of blood coagulation in real time. A paper based on their work was published in the International Journal of Nanomedicine.1
A tracer-based imaging modality that exploits the non-linear interaction between magnetic nanoparticles (MNP) and both static and time-varying magnetic fields. the core feature of MPI is the background-free measurement and visualization of the spatial distribution of MNP. These MNP are typically superparamagnetic iron oxide nanoparticles. As a radiation-free preclinical imaging technique, MPI shows great possibilities for a wide range of clinical applications, including cardiovascular imaging, the monitoring of endovascular interventions, cerebral imaging, and cell tracking.2-8
For this study, blood samples from five volunteers were mixed with the commercial magnetic resonance imaging contrast agent Resotran. The dynamics of the particle signal were assessed in a custom-built MPS-system for a duration of 45 minutes under a variety of conditions, including the presence of anticoagulants (ethylenediamine tetraacetic acid [EDTA], Heparin, Citrate) and mechanical stress. The signal amplitude of the fifth harmonic of the MPS was analyzed. To ensure exclusion of potential thermal effects, the temperature inside the MPS was monitored by using a fiber optic thermometer during the measurements. Analysis revealed that all the Resotran-containing blood samples showed, over time, a signal decrease. Samples with anticoagulants presented no relevant signal decrease (EDTA, Citrate) or a smaller decrease (Heparin) when compared to samples without anticoagulants. Furthermore, mechanical stress induced a signal decay in all samples, which further indicated the link between the observed MPS signal decay and blood coagulation.1
“This study,” write the authors of the paper,1 “shows that continuous monitoring of human blood coagulation via MPS is feasible, making bedside coagulation monitoring in clinical settings a concrete perspective.”
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References
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