Abstract Determining the brain perfusion is an important task for diagnosis of vascular diseases such as occlusions and intracerebral haemorrhage. Even after successful diagnosis, there a high risk restenosis or rebleeding that patients need intense attention in days treatment. Within this work, we present diagnostic tomographic imager allows access to quantitatively short intervals. The device based on magnetic particle imaging technology designed human scale. It highly sensitive detection...

The fast and accurate assessment of cerebral perfusion is fundamental for the diagnosis successful treatment stroke patients. Magnetic particle imaging (MPI) a new radiation-free tomographic method with superior temporal resolution, compared to other conventional methods. In addition, MPI scanners can be built as prehospital mobile devices, which require less complex infrastructure than computed tomography (CT) magnetic resonance (MRI). With these advantages, could accelerate treatment,...

Abstract Superparamagnetic iron-oxide nanoparticles can be used in medical applications like vascular or targeted imaging. Magnetic particle imaging (MPI) is a promising tomographic technique that allows visualizing the 3D nanoparticle distribution concentration non-invasive manner. The two main strengths of MPI are high temporal resolution and sensitivity. While first has been proven assessment dynamic processes cardiac imaging, it unknown how far detection limit lowered. Within this work,...

Magnetic particle imaging (MPI) is an innovative radiation-free tomographic method providing excellent temporal resolution, contrast, sensitivity, and safety. Mobile human MPI prototypes suitable for continuous bedside monitoring of whole-brain perfusion have been developed. However, the clinical translation MPI, a crucial gap in knowledge still remains: while can visualize reduction blood flow tissue cerebral ischemia, it unclear whether works intracranial hemorrhage. Our objective was to...

The use of superparamagnetic iron oxide nanoparticles (SPIONs) has provided new possibilities in biophysics and biomedical imaging technologies. magnetization dynamics SPIONs, which can be influenced by the environment, are central interest. In this work, different biological SPION environments used to investigate three calibration methods for stem cell monitoring magnetic particle imaging. It is shown that calibrating using SPIONs immobilized via agarose gel or intracellular uptake results...

Magnetic particle imaging is a tomographic technique capable of measuring the local concentration magnetic nanoparticles that can be used as tracers in biomedical applications. Since MPI still at very early stage development, there are only few systems worldwide primarily operated by technical research groups develop themselves. It therefore difficult for researchers without direct access to an system obtain experimental data. The purpose OpenMPIData initiative make data freely accessible...

Objectives Fat quantification by dual-energy computed tomography (DECT) provides contrast-independent objective results, for example, on hepatic steatosis or muscle quality as parameters of prognostic relevance. To date, fat has only been developed and used source-based DECT techniques fast kVp-switching CT dual-source CT, which require a prospective selection the imaging mode. It was purpose this study to develop material decomposition algorithm in phantoms validate it vivo patient liver...

Magnetic particle imaging visualizes the spatial distribution of superparamagnetic nanoparticles. Because its key features excellent sensitivity, high temporal and resolution biocompatibility tracer material it can be used in multiple medical applications. The common reconstruction technique for Lissajous-type trajectories uses a system matrix that has to previously acquired time-consuming calibration scan, leading long downtimes scanning device. In this work, is determined by hybrid...

Aim: Magnetic particle imaging (MPI) is highly promising for biomedical applications, but optimal tracers MPI, namely superparamagnetic iron oxide-based contrast agents, are still lacking. Materials & methods: The encapsulation of commercially available nanoparticles, specifically synomag®-D and perimag®, into human red blood cells (RBCs) was performed by a hypotonic dialysis isotonic resealing procedure. amounts oxide incorporated RBCs were determined Fe quantification using nuclear...

Due to peripheral nerve stimulation, the magnetic particle imaging (MPI) method is limited in maximum applicable excitation-field amplitude. This turn leads a limitation of size covered field view (FoV) few millimeters. In order still capture larger FoV, MPI capable rapidly acquire volumes multi-patch fashion. To this end, small excitation volume shifted through space using focus fields. Recently, it has been shown that individual patches are preferably reconstructed joint fashion by solving...

Magnetic Particle Imaging (MPI) is an emerging technology in the field of (pre)clinical imaging. The acquisition a particle signal realized along specific sampling trajectories covering defined view (FOV). In system matrix (SM) based reconstruction procedure, commonly used path MPI Lissajous trajectory. Such trajectory features inhomogeneous coverage FOV, i.e. center region sampled less dense than regions towards edges FOV. Conventionally, respective SM and subsequent do not reflect this...

Magnetic Particle Imaging (MPI) is a novel and versatile imaging modality developing towards human application. When up-scaling to size, the sensitivity of systems naturally drops as coil depends on bore diameter. Thus, new methods push limit further have be investigated cope for this loss. In paper dedicated surface mice developed, improving in cerebral applications. Similar MRI developed improves due closer vicinity region interest. With presented work, it possible image tracer samples...

Magnetic particle imaging (MPI) is a tomographic technique for determining the spatial distribution of superparamagnetic nanoparticles. Current MPI systems are capable iron masses over wide dynamic range more than four orders magnitude. In theory, this could be further increased using adaptive amplifiers, which prevent signal clipping. While applies to single sample, severely limited if several samples with different concentrations or strongly inhomogeneous distributions considered. One...

Magnetic particle imaging (MPI) is an modality that detects the response of a distribution magnetic nanoparticle tracers to alternating fields. There has recently been exploration into multi-contrast MPI, in which signal from different tracer materials or environments separately reconstructed, resulting multi-channel images could enable temperature viscosity quantification. In this work, we apply reconstruction technique discriminate between core sizes. Three types with diameters 21.9 nm,...

Image reconstruction plays an important role for the tomographic imaging technique magnetic particle (MPI) since measured raw data cannot be directly interpreted. Instead, one needs to invert image formation process, which involves solution of ill-conditioned linear system equations. Currently, most MPI researchers have implemented custom algorithms that compared source code is not openly available. The software package MPIReco.jl aims change this situation by providing a reference...

The tomographic imaging method magnetic particle (MPI) requires a multi-patch approach for capturing large field of views. This consists continuous or stepwise spatial shift small sub-volume only few cubic centimeters size, which is scanned using one multiple excitation fields in the kHz range. Under assumption ideal fields, MPI system matrix invariant and turn single suffices image reconstruction significantly reducing calibration time effort. For imperfections, however, can lead to severe...

Improving resolution and sensitivity will widen possible medical applications of magnetic particle imaging. Pulsed excitation promises such benefits, at the cost more complex hardware solutions restrictions on drive field amplitude frequency. State-of-the-art systems utilize a sinusoidal to superparamagnetic nanoparticles into non-linear part their magnetization curve, which creates spectrum with clear separation direct feed-through higher harmonics caused by particles response. One...

Abstract The image reconstruction problem of the tomographic imaging technique magnetic particle (MPI) requires solution a linear inverse problem. One prerequisite for this task is that operator describes mapping between and measured signal accurately known. For 2D 3D excitation patterns, it common to measure system matrix in calibration procedure, both, very time consuming adds noise operator. need measuring due lack an accurate model capable describing nanoparticles’ magnetization behavior...

Vascular interventions are a promising application of Magnetic Particle Imaging enabling high spatial and temporal resolution without using ionizing radiation. The possibility to visualize the vessels as well devices, especially at same time multi-contrast approaches, enables higher accuracy for diagnosis treatment vascular diseases. Different techniques make devices MPI visible have been introduced so far, such varnish markings or filling balloons. However, all approaches include challenges...

The imaging technology magnetic particle allows the detection of material, in particular superparamagnetic nanoparticles, by remagnetization material via fields. application is aimed at medical where particles are applied as tracer directly into blood stream. Medical safety considerations such peripheral nerve stimulation limit maximal amplitude fields and turn field view size. To handle this constraint concept patches was introduced, which a shift to different positions order enlarge area....

Objective.Magnetic particle imaging (MPI) is capable of high temporal resolution measurements the spatial distribution magnetic nanoparticles and therefore well suited for perfusion imaging, which an important tool in medical diagnosis. Perfusion MPI usually requires a fresh bolus tracer material to capture key signal dynamics. Here, we propose method decouple sequence from injection additional material, without further increasing administered iron dose body with each image.Approach.A...

Magnetic particle imaging is a tomographic modality capable of determining the distribution magnetic nanoparticles with high temporal resolution. The spatial resolution influenced by gradient strength selection field used for encoding. By increasing strength, improved, but at same time volume decreases. For high-resolution image an extended field-of-view, multipatch approach can be shifting sampling trajectory in space. As total timescales number patches, downside method degradation...