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Item type:Publication, Access status: with files , Topology considerations for an iron-core coil module field generator(Infinite Science Publishing, 2026-03-18); ; ; ; The selection-field generator of a Magnetic Particle Imaging (MPI) scanner is typically the system’s largest power consumer. For potential use in intensive care units, it would be highly desirable to operate MPI scanners from a standard wall outlet without dedicated high-power infrastructure. Several concepts for more efficient selection-field generation have been proposed in recent years. In this work, we propose a novel generator design based on an array of soft-iron core coils arranged at an angle around the scanner bore. This geometry reduces overall electrical power demand while enabling gradient strengths of up to 0.5 T m¹. The design was simulated and optimized using magnetostatic simulations in COMSOL Multiphysics. To ensure reliable modeling of the soft-iron cores, prototype coils were built and their magnetic fields were measured, providing experimental validation of the simulation models.Publicationtype: Journal Article8 7 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , A low-noise differential JFET amplifier for magnetic particle imaging(Infinite Science Publishing, 2026-03-18); ; ; ; In MPI systems designed for large areas of the human body, drive fields are a significant source of interference for the receive electronics. Their influence, in addition to the direct feedthrough of the signal, can manifest itself in the form of common-mode noise, which can be effectively suppressed using filters and low-noise amplifiers with a differential architectures. In this work, we demonstrate a prototype of a low-noise amplifier based on a differential first stage, which works in combination with fourth-order notch receive filter. Our preliminary results show a gain of at least 40 dB over the frequency range of 50-700 kHz, effectively covering measurable harmonic signals for head-sized MPI scanner.Publicationtype: Journal Article12 10 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Comparison of human-scale MPI system concepts using a 3D arbitrary-waveform magnetic particle spectrometer(Infinite Science Publishing, 2026-03-18); ; ; In the field of Magnetic Particle Imaging (MPI) hybrid methods are utilizing the simplicity and high SNR of magnetic particle spectrometers to complement imaging by characterizing particles and measuring system matrices for fast system calibration. In this contribution we utilize the flexibility of our 3D arbitrary-waveform magnetic particle spectrometer to measure the system matrices of three MPI scanner concepts inspired by clinical-scale head-sized MPI systems. Using these system matrices we are able the compare reconstructed images under the same noise, particle and reconstruction conditions gathering first insights into the imaging properties of different scanners.Publicationtype: Journal Article12 8 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Normalized quantitative assessment of receive-coil sensitivity using MPI transfer function measurements(Infinite Science Publishing, 2026-03); ; ; ; In human-scale magnetic particle imaging (MPI), field inhomogeneities arise because a large fraction of the bore volume is utilized for imaging. Accurate knowledge of the receive-coil sensitivity is essential for hybrid systemmatrix generation and model-based system matrix reconstruction. In this work, we present an efficient approach for measuring normalized receive-field profiles using a calibration coil and a small number of measurements.Publicationtype: Conference Paper14 9 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Spherical harmonic-based receive coil array for a head MPI system(Infinite Science Publishing, 2026-03); ; ; ; A gradiometric receive coil is practically the modern standard in MPI. Although such a structure is one of the reliable and most effective ways of isolating the receive circuits from the influence of drive fields, it is challenging to implement it for the spatial sensitivity directions orthogonal to the cylinder axis of an MPI scanner. In this work, we demonstrate a concept of matrix coils based on spherical harmonic spatial sensitivity profiles. Our approach permits us to expand the number of independent receive channels in our head-sized MPI system to seven (and potentially more), while preserving important gradiometric characteristics of each channel.Publicationtype: Conference Paper10 7 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Continuous coagulation monitoring in human blood samples via magnetic particle spectroscopy(Dove Medical Press Ltd, 2026-02-25); ; ; ; Introduction: Magnetic Particle Imaging (MPI) is a radiation-free imaging modality based on the nonlinear magnetic response of iron oxide nanoparticles, providing high sensitivity and real-time, quantitative, background-free imaging. With the clinical approval of 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 this pilot study, we prove the potential of MPS to continuously monitor blood coagulation in real time. Methods: 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 various conditions, including the presence of anticoagulants (EDTA, Heparin, Citrate) and mechanical stress. The signal amplitude of the fifth harmonic of the MPS was analyzed. To exclude potential thermal effects, the temperature inside the MPS was monitored by using a fiber optic thermometer during the measurements. Results: All Resotran-containing blood samples showed a signal decrease over time. Samples with anticoagulants exhibited no relevant signal decrease (EDTA, Citrate) or a smaller decrease (Heparin) compared to samples without anticoagulants. Additionally, mechanical stress induced a signal decay in all samples, further indicating the link between the observed MPS signal decay and blood coagulation. Conclusion: This study shows that continuous monitoring of human blood coagulation via MPS is feasible, making bedside coagulation monitoring in clinical settings a concrete perspective.Publicationtype: Journal Article7 7 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Towards picogram detection of superparamagnetic iron-oxide particles using a gradiometric receive coil(Jenny Stanford Publishing, 2026-01-01); ; ; ; Superparamagnetic iron-oxide nanoparticles can be used in medical applications like vascular or targeted imaging. Magnetic particle imaging (MPI) is a promising tomographic imaging technique that allows visualizing the 3D nanoparticle distribution concentration in a non-invasive manner. The two main strengths of MPI are high temporal resolution and high sensitivity. While the first has been proven in the assessment of dynamic processes like cardiac imaging, it is unknown how far the detection limit of MPI can be lowered. Within this work, we will present a highly sensitive gradiometric receive-coil unit combined with a noise-matching network tailored for the imaging of mice. The setup is capable of detecting 5 ng of iron in-vitro with an acquisition time of 2.14 sec. In terms of iron concentration we are able to detect 156 µg/L marking the lowest value that has been reported for an MPI scanner so far. In-vivo MPI mouse images of a 512 ng bolus and a 21.5 ms acquisition time allow for capturing the flow of an intravenously injected tracer through the heart of a mouse. Since it has been rather difficult to compare detection limits across MPI publications we propose guidelines to improve the comparability of future MPI studies.Publicationtype: Book Part4 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Magnetic particle imaging for real-time perfusion imaging in acute stroke(Jenny Stanford Publishing, 2026-01-01); ; ; ; The fast and accurate assessment of cerebral perfusion is fundamental for the diagnosis and successful treatment of stroke patients. Magnetic particle imaging (MPI) is a new radiation-free tomographic imaging method with a superior temporal resolution, compared to other conventional imaging methods. In addition, MPI scanners can be built as prehospital mobile devices, which require less complex infrastructure than computed tomography (CT) and magnetic resonance imaging (MRI). With these advantages, MPI could accelerate the stroke diagnosis and treatment, thereby improving outcomes. Our objective was to investigate the capabilities of MPI to detect perfusion deficits in a murine model of ischemic stroke. Cerebral ischemia was induced by inserting of a microfilament in the internal carotid artery in C57BL/6 mice, thereby blocking the blood flow into the medial cerebral artery. After the injection of a contrast agent (superparamagnetic iron oxide nanoparticles) specifically tailored for MPI, cerebral perfusion and vascular anatomy were assessed by the MPI scanner within seconds. To validate and compare our MPI data, we performed perfusion imaging with a small animal MRI scanner. MPI detected the perfusion deficits in the ischemic brain, which were comparable to those with MRI but in real-time. For the first time, we showed that MPI could be used as a diagnostic tool for relevant diseases in vivo, such as an ischemic stroke. Due to its shorter image acquisition times and increased temporal resolution compared to that of MRI or CT, we expect that MPI offers the potential to improve stroke imaging and treatment.Publicationtype: Book Part6 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Software implementation of greedy optimized MPS sequences(Infinite Science Publishing, 2025-03-14); ; ; ; Multi-dimensional magnetic particle spectrometers provide fast and high quality hybrid system matrix measure-ments, using different DC offsets to emulate the same saturation that magnetic nanoparticles are exposed to in a real scanner or during particle characterization. In this work, we address the challenges of minimizing sign changes of DC sources with H-bridges and slow rise times. We provide a generic offset sorting scheme for an arbitrary number of channels. Our implementation allows a variety of devices to be controlled using the same software interface.Publicationtype: Journal Article8 8 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Correction to: System characterization of a human-sized 3D real-time magnetic particle imaging scanner for cerebral applications (Communications Engineering, (2024), 3, 1, (47), 10.1038/s44172-024-00192-6)(Springer, 2024-12); ; ; ; Correction to: Communications Engineeringhttps://doi.org/10.1038/s44172-024-00192-6, published online 14 March 2024 Author correction: In the original version of this Article, financial support from the Open Access Publication Fund of UKE - Universitätsklinikum Hamburg-Eppendorf was not acknowledged. This has now been corrected in both the PDF and HTML versions of the Article. The Acknowledgements section needs to be revised to: We thank Florian Sevecke for technical support during the realization of numerous scanner components. We further thankfully acknowledge the financial support by the German Research Foundation (DFG, grant numbers KN 1108/7-1 and GR 5287/2-1). We also thank the developers of Makie.jl supporting us by answering technical questions when creating Figs. 3 and 4. Finally, we are grateful to Christian Findeklee for their discussions and insights into resonant circuit decoupling. We acknowledge financial support from the Open Access Publication Fund of UKE - Universitätsklinikum Hamburg-Eppendorf.Publicationtype: Corrigendum41 19