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Magnetic Particle Imaging (MPI) is a fast imaging technique for the visualization of the distribution of superparamagnetic iron-oxide nanoparticles (SPIONs) in 3D. For spatial encoding, a field free area is moved rapidly through the field of view (FOV) generating a localized signal. Fast moving samples, e.g., a bolus of SPIONs traveling through the large veins in the human body carried by blood flow with velocities in the order of ~45 cm/s and higher, cause temporal blurring in MPI measurements using common sequences and reconstruction techniques. This hampers the evaluation of dynamics of rapidly moving samples. In this abstract, initial results of rapidly moving samples in form of SPION boluses visualized within an MPI scanner are shown., International Journal on Magnetic Particle Imaging IJMPI, Vol 9 No 1 Suppl 1 (2023)

Phantoms of blood vessels are an important part of flow measurements and should behave as realistic as possible compared to human blood vessels. A step-by-step guide is presented on how to obtain realistic 3D models of blood vessels applicable for 3D printing and simulation studies. The resulting 3D models have realistic dimensions, are waterproof and could be used in a human-sized MPI scanner. The 3D printed phantoms with vascular pathologies like aneurysm or stenosis were used in static and real-time bolus tracking measurements., International Journal on Magnetic Particle Imaging IJMPI, Vol 9 No 1 Suppl 1 (2023)

MPI has been on a trajectory towards clinical application in humans for years. As scanners and techniques mature, clinical testing is effectively prohibited by the lack of a clinically approved tracer. This changes now by the reintroduction of a Ferucarbotran-based tracer into the market, Resotran®. Although initially intended for use in MRI, we tested Resotran® for its viability in MPI. The other Ferucarbotran-based tracer fit for MRI and MPI is Resovist®, which is well known and characterized but was discontinued years ago. We present initial data on the characterization of Resotran® in comparison to Resovist®., International Journal on Magnetic Particle Imaging IJMPI, Vol 9 No 1 Suppl 1 (2023)

Based on a novel open design implementing the so-called traveling wave MPI approach, the open interventional MPI (iMPI) system provides imaging of tracers based on superparamagnetic iron oxide nanoparticles (SPIONs) with high sensitivity, optimal patient handling and would even allow hybrid imaging of magnetic tracers within gold standard x-ray based interventional angiography systems. In initial experiments, the feasibility of a human-sized interventional MPI scanner with real-time data reconstruction and image visualization is demonstrated within a percutaneous transluminal angioplasty (PTA)., International Journal on Magnetic Particle Imaging IJMPI, Vol 9 No 1 Suppl 1 (2023)

Endovascular treatment of human aneurysms with stent grafts is an established therapeutic strategy to treat ruptured and unruptured arterial aneurysms. These stents are covered with a membrane that blocks blood flow to the aneurysm and promotes healing of the vessel. To date, digital subtraction angiography (DSA) has been gold standard for image-guided stent graft application. However, DSA is associated with significant disadvantages including its invasiveness, the need for potentially nephrotoxic iodine-based contrast agents and exposure to ionizing radiation for patients and clinical staff. Magnetic particle imaging (MPI) is a fast and sensitive tomographic imaging technique that uses magnetic fields to visualize superparamagnetic iron-oxide nanoparticles (SPIONs). The advantages of MPI include the background- and radiation-free visualization of SPION-tracers. The aim of this proof-of-concept study was to demonstrate the potential of MPI for image-guided application of covered stents in a 3D printed realistic aneurysm phantom., International Journal on Magnetic Particle Imaging IJMPI, Vol 9 No 1 Suppl 1 (2023)

Investigation of influence of metallic endoprostheses on MPI functionality in a human-sized MPI scanner. No relevant impairment of imaging from the presence of endoprosthesis could be found., International Journal on Magnetic Particle Imaging IJMPI, Vol 9 No 1 Suppl 1 (2023)

Magnetic Particle Imaging (MPI) has become a promising candidate for medical applications, especially cardiovascular interventions. Necessary milestones have been reached in multiple pre-clinical experiments and studies and are ready to be tested on human-scale MPI scanners. Only few human-sized scanner systems designed for dedicated applications are available. In this abstract, a novel approach is presented for a dedicated human-sized interventional MPI scanner., International Journal on Magnetic Particle Imaging, Vol 8 No 1 Suppl 1 (2022)

4D flow experiments, as known from MRI, are useful to examine the fluid dynamics in complex vessel geometries with high accuracy. The transfer to a positive contrasted fast and sensitive modality, such as MPI, offers new insights into dynamic particle flow under real-time visualization. In particular, measurements in 3D printed vascular phantoms are beneficial since they allow studies of the complicated flow-related interrelations causing the development of pathologies and also provide a quality control for the development of more realistic vascular phantoms. The presented framework provides an easy-to-use processing from extraction of desired vessel structures from 3D MRI or CT data over preparation them for 3D printing and further processing to final measurements., International Journal on Magnetic Particle Imaging, Vol 8 No 1 Suppl 1 (2022)

Diese Diplomarbeit ist eine kontextuelle Ausarbeitung ��ber die architektonischen Wertigkeiten des t��glichen Lebens, die die st��dtischen Schaupl��tze f��r die augenf��llig festgelegten Gegebenheiten erkundet und diese mit Mitteln der modernen Medien in anschaulicher erz��hlend Form in Beziehung setzt. Es wird nach der Basis gesucht, auf der die Entscheidungen ��ber die Begrifflichkeit von Schuld bzw. Scham, im Heute und Jetzt konsequenterweise getroffen werden k��nnen. Diese werden im Abschreiten des Kunstprojektes ���Weg der Erinnerung durch die Leopoldstadt��� untersucht, das sich mit dem Holocaust auseinandersetzt. Aus diesem Grund wird der Mensch als solcher in den Vordergrund geschoben und die daraus folgenden Erkenntnisse werden zu einer neuen, humanistisch gepr��gten Verhaltensweise zusammengef��gt. Dadurch wird der Blick auf die Architektur in Richtung einer, den heutigen und zuk��nftigen Anspr��chen gerecht werdende, Ebene gelenkt., This is a contextual elaboration about the architectural values of the daily life, which examines urban venues for obvious set conditions and interrelate these with the use of modern media in a clear, narrative form. Furthermore, this thesis is trying to create an initial situation, on which decisions about the conception in context of guilt and shame can consequently be made for the present. This is examined by placing off the art project "The Street Of Memento", which approaches the holocaust. In honor of this special emphasis is placed on human beings and consequently, perceptions will be merged into a new human condition. Thereby the view on architecture is drawn to a level which meets todays and future requirements.

Magnetic Particle Imaging is a tomographic imaging technique offering high sensitivity and temporal resolution and is a promising tool for pre-clinical applications. The state of the art Traveling Wave Magnetic Particle Imaging (TWMPI) scanners offer a mouse-sized FOV, which can be scanned at once. Since the first introduction of TWMPI, several sequences have been introduced to scan the FOV in 2D as well as 3D. So far, the proposed 3D sequences do not provide real-time capability, which is an important feature for future clinical applications such as guided vascular interventions. In this study a modified sequence for TWMPI scanners is presented, which allows scanning an entire 3D volume on a short time scale. Furthermore, for real-time capability a novel reconstruction method using an image-based approach is used providing a 3D visualization in real-time. sion of mutual interferences and their impact on image quality of both modalities., International Journal on Magnetic Particle Imaging, Vol.3, No.2, Article ID 1706001

Many MPI scanners have difficulties to correctly visualize areas with a broad signal intensity spectrum due to their low signal dynamic capability. This effect is caused by analog-digital-converters (ADC) which are required for digitizing raw analog signals and are limited in their dynamic range. In Lissajou-trajectory MPI scanners this issue can be addressed by scanning small patches out of a large field of view (FOV) and adjusting the dynamic range for every patch separately. In traveling wave MPI (TWMPI) an elongated dynamic linear gradient array (dLGA) is used for the generation of field free points allowing to scan a relatively large FOV with a relatively short acquisition time. To date the patch concept cannot easily be transformed to TWMPI. However, the signal can be selectively suppressed by locally reducing the speed of the FFPs due to the modular design of the TWMPI scanner. In this study a dynamic drive field forming technique for TWMPI is introduced which allows to focus on low SPIO concentrations in samples with a large range of tracer concentrations. This could facilitate preclinical functional imaging in the proximity of organs with high unspecific SPIO uptake such as the liver., International Journal on Magnetic Particle Imaging, Vol.3, No.2, Article ID 1709001

In the last decade research in the Magnetic Particle Imaging community focused mainly on hardware development as well as the optimization of reconstruction. These steps were essential for improving MPI technology and advance it to pre-clinical applications. However, another important part is the software package working behind MPI systems. This software has to be able to keep up with modern scanner features and should be able to support features such as adjustable scanning trajectories or multiple reconstruction methods. Especially a real-time reconstruction feature is important to use the full potential of the fast imaging capabilities of modern MPI scanners. This could be pivotal in applications such as guided vascular interventions. In this work, a software package is presented, which improves reconstructing MPI data with different reconstruction methods in real-time and with low latency., International Journal on Magnetic Particle Imaging, Vol.3, No.2, Article ID 1707002

Dieses Projekt soll zur Entwicklung eines Bluttests beitragen, um bei allogen stammzelltransplantierten (allo-SZT) Patienten eine drohende akute Graft-versus-Host Disease (aGVHD) vorhersagen und von einer Infektionskomplikation unterscheiden zu können. Die aGVHD und opportunistische Infektionen, wie etwa eine Zytomegalievirus- Infektion, stellen die Hauptrisiken der allo-SZT dar. Eine durch einen prädiktiven Test verbesserte Vorhersage bzw. Differenzierung dieser beiden schweren omplikationen könnte zu einem breiteren Einsatz der allo-SZT führen. Eine Reihe von Erkenntnissen lassen die Vermutung zu, dass bestimmte Homing- Rezeptoren auf T-Zellen im peripheren Blut als Marker zur Vorhersage und Differenzierung zwischen einer aGVHD und Infektionskomplikationen dienen könnten. So wurde in Mausmodellen gezeigt, dass die Pathogenese der aGVHD ein streng zeitlich regulierter und organspezifischer Immunprozess ist. Alloreaktive T-Zellen müssen bestimmte Homing-Rezeptoren exprimieren, um in die Zielorgane der aGVHD (Gastrointestinaltrakt, Leber und Haut) einwandern zu können. Die Immunreaktion auf eine Infektion setzt ebenfalls voraus, dass in der adaptiven Immunantwort T-Zellen organ- und entzündungsspezifische Homing-Rezeptoren exprimieren. Eine zentrale Voraussetzung für einen prospektiven klinischen Test mit allo-SZT Patienten ist die Kenntnis der physiologischen Bandbreite der Oberflächenmarker auf T-Lymphozyten in Gesunden, um diese von pathophysiologischen Veränderungen unterscheiden zu können. Ziel dieser Arbeit war es daher, eine effiziente und zuverlässige Methode zu entwickeln, um das Homing-Rezeptor-Profil von humanen T-Zellen im peripheren Blut analysieren zu können. Dazu wurde ein urchflusszytometrie-Test mit 25 Oberflächenmarkern etabliert, die eine Rolle in der Pathogenese der aGVHD und bei Infektionen spielen könnten. Mit diesem Test wurde die Expression der Oberflächenmarker von 21 gesunden Probanden an 8 Zeitpunkten über einen Zeitraum von 3 Wochen analysiert. Die untersuchten Oberflächenmarker lassen sich dabei entsprechend ihrer Expressionsmuster in drei Kategorien einteilen, nämlich (I) zeitlich stabile niedrige, (II) zeitlich stabile hohe und (III) dynamisch schwankende Expression. Aufbauend auf diesen Ergebnissen für gesunde Probanden wurde am Universitätsklinikum Würzburg eine prospektive klinische Studie an aGVHD-Patienten begonnen., This project contributes to the development of a blood test to predict acute graft-versus- host disease (aGvHD) and to differentiate it from infectious complications in allogeneic hematopoietic cell transplantation (allo-HCT). aGvHD and opportunistic infections like Cytomegalovirus infections are major risks of allo-HCT. Such a predictive test could bring a major improvement in the prevention and treatment of aGvHD. The basic idea of this test is that certain homing receptors on peripheral blood T cells could serve as markers to predict and to differentiate between aGvHD and opportunistic infections. This is supported by several empirical findings. It has been recently demonstrated in murine in vivo imaging models that aGvHD pathogenesis is an organ specific process that is tightly regulated in time. Alloreactive T cells express certain homing receptors in order to reach the aGvHD target organs (intestinal tract, liver and skin). Also the immune response to an infection requires the expression of specific homing receptors on T cells. For a prospective clinical test with allo-HCT patients it is important to establish the physiological ranges of T cell surface markers of healthy individuals, to distinguish them from pathological changes. This project intends to establish an efficient and reliable method to analyze the homing receptor profile of human peripheral blood T cells. A multiplex flow cytometry test for cytotoxic and T helper cell subsets was developed to analyze the expression of 25 activation markers, organ specific homing receptors and inflammatory response receptors on human peripheral blood T cells that are likely to play a role in the pathogenesis of aGvHD and infections. With this test the surface marker profile of 21 healthy individuals was analyzed. The peripheral blood mononuclear cells were examined by flow cytometry at 8 points in time within 3 weeks. Preliminary mouse experiments in our group suggested these points in time as critical for subsequent prospective clinical studies. We found that the surface marker expression on peripheral blood cytotoxic and T helper cells in healthy probands can be subdivided into 3 categories: (I) constant low expression, (II) constant high expression and (III) T cell subsets that dynamically change the expression. These findings for healthy probands form the basis for a recently initiated clinical prospective study with allo-HCT patients at the University Hospital Würzburg.