International Journal on Magnetic Particle Imaging (IJMPI)
Not a member yet
555 research outputs found
Sort by
Enzyme-powered magnetic nanomotors for magnetic particle imaging and magnetic fluid hyperthermia
No full textMagnetic fluid hyperthermia (MFH) is a promising cancer therapy that relies on the heat dissipation of magnetic nanoparticles. To enhance the efficiency of MFH, materials with improved penetration and diffusion properties are required. Self-propelled nanomotors (NMs), driven by catalytic reactions, offer significant potential in this regard. Urease-powered nanomotors have demonstrated enhanced accumulation in tumors and improved therapeutic outcomes. This work presents a novel urease-powered magnetic nanomotor that functions as both a tracer for magnetic particle imaging (MPI) and a magnetic material for hyperthermia. The proposed nanomotor exhibits efficient diffusion and magnetic heating, making it an ideal candidate for MPI-assisted MFH therapy
GPU Accelerated Multi-Patch Reconstruction
No full textThe multi-patch approach in magnetic particle imaging is used to capture large field of views. System-matrix-based image reconstruction for this approach often considers a joint system of equations to minimize artifacts. Due to the prohibitive size of this inverse problem, reconstructions rely on iterative algorithms that do not need to keep the entire system matrix in memory. This work shows a graphical processing unit accelerated implementation of a generalized multi-patch operator. The achieved runtime improvements allow for multi-patch reconstructions using different optimization algorithms, which in turn allow for a flexible choice of regularization terms
System function analysis of MPI with Field-Free Line and excitation coil configurations
No full textMagnetic Particle Imaging (MPI) visualizes the distribution of magnetic particles using their nonlinear magnetization response. This study evaluated the impact of interference between the Field-Free Line (FFL) and alternating excitation field on system performance. The Coaxial Configuration suppressed interference and provided stable in-phase signals, while the Orthogonal Configuration produced anti-phase signals, reducing sensitivity. The Coaxial Configuration is suitable for wide-area measurements, whereas the Orthogonal Configuration offers high resolution but faces sensitivity challenges
Dipolar interaction effect on magnetization harmonics in liner chain magnetic nanoparticles
No full textMagnetic nanoparticles (MNPs) have been widely studied in many bio applications because of their unique magnetic properties. However, the strong dipolar interaction in MNPs affects their magnetic properties. In this work, to investigate the influence of dipolar interaction on the harmonics of magnetization in MNPs we performed numerical simulations in a liner chain MNPs by stochastic Landau-Lifshitz-Gilbert equation. The simulation results show that the third harmonic component of the magnetization is not uniquely determined by the magnitude of dipole interaction field unlike the fundamental component of the magnetization, it is susceptible to the phase lag between external field and dipole interaction field
Single-Chain Architecture in a Multi-Channel Magnetic Particle Spectrometer
No full textMagnetic particle spectrometry (MPS) is a valuable tool for characterizing the magnetic properties of magnetic nanoparticles (MNPs), which significantly affect image resolution in MPI. As a result, extensive research is dedicated to enhancing the magnetic properties of MNPs. This research focuses on the design and development of a multi-channel MPS system with five channels, each operating at 20 mT, to track nucleation and growth processes and to ensure quality control in flow-based synthesis
Design and Implementation of a Novel Surface Excitation Coil for a Single-Sided Field Free Line MPI Scanner
No full textIn MPI, designing whole-body hardware for clinically relevant imaging remains non-trivial. Single-sided scanner designs, which confine hardware to one side of the imaging volume, offer an open imaging volume but suffer from inhomogeneous magnetic fields, resulting in decreased sensitivity and spatial resolution away from the scanner. Here, we redesigned our single-sided field-free line scanner by implementing a novel organ-specific surface excitation coil. This upgrade highlights the potential of the scanner to significantly improve sensitivity and image quality in single-sided MPI applications
Shape-optimized soft-hard tandem tracers for enhanced magnetic particle imaging
No full textMagnetic Particle Imaging (MPI) is a leading molecular imaging technique with unmatched potential for disease diagnosis, offering high contrast and sensitivity without radiation. However, current MPI tracers, such as Vivo Trax and Resovist, have a detection threshold of 100 µM, far from the theoretical 20 nM limit. To address this, we propose a Soft-Strength Tandem (SST) magnetic control strategy using octahedral-IONPs (O-IONPs) to enhance MPI performance. Our O-IONPs reduce surface spin disorder, increasing saturation magnetization (Ms), and their shape influences coercivity (Hc), addressing the balance between these properties. The octahedral shape promotes crystallization behavior that impacts atomic magnetic moments and surface magnetic anisotropy (Ks), essential for Hc. Our tracers achieve comparable imaging to Vivo Trax at significantly lower doses, setting a new paradigm for shape-mediated MPI tracers and unlocking MPI\u27s full diagnostic potential
Thermal Considerations Towards a Highly Flexible Multi-Core Selection and Focus Field Generator
No full textThis paper presents interim results in the development and implementation of a selection and focus field generator for Magnetic Particle Imaging. The construction of a multi-coil field generator specifically designed for the purpose of diffusion imaging of the brain is a complex task. The degrees of freedom in topological decisions with interconnected dependencies require careful considerations. The preliminary results of the initial constructional and electrical concept based on simulations are presented.A focus in decision making was placed on the manufacturability of the coils and their thermal properties. The conducted experiments indicate that the manufacturing and fixation of the core coil module presents a significant challenge. Additionally, more advanced cooling strategies have been pre-evaluated, as the intended cooling setup has been found to be inadequate in the visualized setup
Development of a Magnetically Responsive Polydimethylsiloxane Composite with Optimized SPION Distribution for Coating of Medical Devices
No full textThis study introduces the development of an innovative polydimethylsiloxane (PDMS) composite enhanced with superparamagnetic iron oxide nanoparticles (SPIONs), specifically engineered as a polymer coating for medical devices and as a functional material for Magnetic Particle Imaging (MPI) in diagnostic applications. To achieve uniform spatial dispersion of nanoparticles within the PDMS matrix, ultrasonic treatment was employed, effectively enhancing the homogeneity of SPION distribution throughout the polymer structure. The results demonstrate significant promise for this superparamagnetic composite, offering new avenues in the advancement of polymer-based materials for medical imaging and device technology
An inductive sensor for continuous in-line monitoring of proteolytic cleavage
No full textProteases are an important type of enzyme that chemically cleave proteins and peptides, and can serve as useful biomarkers in both the context of healthcare and some industrial processes. Devices that enable routine and inexpensive measurement of proteolytic cleavage could facilitate ubiquitous protease activity monitoring and offer a wealth of actionable data. In this project, we developed a device intended for liquid samples in which magnetic nanoparticles are bound via cleavable peptides to a chemically modified mm-scale fluidic channel in a disposable glass and PDMS chip situated over an inductive sensor. When an active protease corresponding to the peptide substrate is present in the fluid passing through the device, the magnetic particles are released from the active region of the sensor and exit the device. The sensor, which includes a 7 turn excitation coil and a set of 14-turn gradiometer coils, is entirely formed by highly symmetric traces in an 8-layer printed circuit board. Using 100 µs pulsed fields generated through capacitive discharge and amplifying the output of the gradiometer, we are able to show a limit of detection below 1 µg of iron, and regulate the temperature of the fluidic device by varying the pulse rate to control Joule heating. While further optimization of the sensor is still required, our current prototype exhibits a detection sensitivity below 1 µM for the protease chymotrypsin.