BIOMEDIZINISCHE

MAGNETRESONANZ

It is known from animal work that most mechanisms limiting neural resources manifest at the level of brain microstructure and influence brain functions at different hierarchical levels, such as brain macrostructure, neuronal networks, and behavioural phenotypes. Current research on neural resources in humans, however, often lacks a mechanistic level of explanation due to missing technology and/or methodological expertise needed to describe neuronal changes at the meso-scale (i.e. at the level of cortical layers or neuronal ensembles). This hinders knowledge transfer from mechanistic insights at the micro-scale gained in animal research to macro-scale human brain models and interventions. The CRC initiative has the overall goal to systematically investigate neural resources at the micro-, meso-, and macro-scale by taking an interdisciplinary and multi-scale approach and to link changes in the functional and structural architecture of cortical and subcortical micro-circuits to behavioural performance and cognitive interventions. Technological advancements in meso-scale brain imaging, meso-scale data modelling, and multi-modal and multi-scale data interaction can bridge this gap. The aim of Z02 is to develop and test novel technologies using ultra-high resolution 7 Tesla magnetic resonance imaging (7T MRI) for wider applications in human subjects and primates and to provide them to the researchers of the CRC projects by ensuring (i) usage of appropriate and state-of-the-art MR-sequences that offer reproducible and optimised data quality and (ii) computational tools and analysis pipelines for multi-modal and multi-scale data modelling within and across individuals. Z02 has the overarching goal of modelling the human cortex in three dimensions, that is, both in plane at the cortical surface (dimensions 1&2) and in cortical depth (dimension 3, cf. Kuehn & Sereno 2018, Fig. 1). This approach extends the frequently applied localisation of function in cortical regions, e.g. Brodmann areas, or more advanced and ambitious columnar mapping, to a novel level of detail relevant for cognitive processes (e.g., Larkum et al. 2018). This will allow the CRC projects to target research questions on neural resources in a novel yet undiscovered dimension, while at the same time enabling Magdeburg to maintain its leading position for human brain imaging in Europe.

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Research areas
Biomedical Technology and Medical Physics (205-32)
Biomedical System Technology (407-06)

Due to the limited accessibility of the bulk material to direct detection methods, often only integral flow quantities can be measured at the inlet and outlet of packed bed reactors. The exact understanding of the processes inside these technical systems is, thus, just as difficult as the system design with regard to energy efficiency and product quality. Furthermore, predictions from simulations cannot be experimentally validated in detail. Therefore, in project A2 the three-dimensional (3D) velocity field of the gas flow will be first measured in the reference configuration of the CRC/TRR with spherical and complex shaped particles by means of hyperpolarised phase contrast magnetic resonance imaging (pc-MRI). Three-dimensional, temporally and spatially resolved flow maps of the entire gas volume will be generated. These flow field data are essential and form the basis for the further understanding of the homogeneous and heterogeneous chemical reaction rates in particle beds. Sensors or tracer particles, which in turn can perturb the flow and particle movement, are not required. Optical access is also not necessary and arbitrary geometries are possible. The high flexibility of pc-MRI allows adaptations of the measurement to the requirements, e.g. regarding the sample volume (up to about 40 x 40 x 40 cm in commercial MRI) and the spatial (approx. 1 millimetre) or temporal resolution (approx. 1/10 second). With established MRI methods, usually only liquids can be detected due to their favourable physical properties with regards to generation of magnetisation (also called spin polarisation) and its life-time (relaxation properties). In this project, the transition to gaseous media is made possible by the application of highly innovative hyperpolarisation techniques. With this, the comprehensive three-dimensional, quantitative measurement of gas flow fields in complex geometries of non-transparent particle beds will be possible for the first time. Therefore, in addition to hyperpolarisation of the gas, MRI flow measurement methods for hyperpolarised magnetisation must be established. In addition, the development of materials and measurement setups is required that support the use of hyperpolarised gases without interference with the high spin polarisation. A2 will, therefore, build a continuous flow Xenon hyperpolariser with sufficient flow and polarisation level for fast and accurate MRI detection of gas (WP 1), a Xe-coil for Xe-MRI (WP 2), select and characterise proper materials for building an MR-compatible reference experiment (WP 3), extend a table to MR system for Xe-capability (WP 4), develop 3D pc-MRI flow measurement method for the application in hyperpolarised gas systems (WP 5) and measure and process flow data from the reference configuration (WP 6) to be provided to the simulation projects and to be compared to the other experimental methodology.

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Die Ultrahochfeld-Magnetresonanztomographie ist eine fortschrittliche medizinische Bildgebungstechnologie und spielt eine wichtige Rolle in der Erforschung der Gehirnfunktion und Neurobiologie. Sie ermöglicht Wissenschaftlern, detaillierte Bilder des Gehirns zu erfassen und funktionelle Aktivitäten in Echtzeit zu verfolgen. Dies kann zu einem besseren Verständnis von Gehirnerkrankungen, kognitiven Prozessen und neurologischen Störungen beigetragen. Das technische Ziel dieses Projektes ist die Realisierung einer universellen integrierten Konsole für Hochfeld-MRT-Systeme. Die in diesem Projekt entwickelte MRT-Konsole übertrifft alle bisher kommerziell oder als Eigenbau verfügbaren Systeme und ermöglicht es der OVGU und damit dem Land Sachsen-Anhalt, die Leuchtturmaktivitäten im Bereich MRT und Neurowissenschaften in den kommenden Jahren auszubauen und zu sichern. Ferner bietet das Projekt eine exzellente Möglichkeit der Einbindung in die
Hightech-Strategie des Landes Sachsen-Anhalt mit der Ansiedlung von Konzernen der Halbleitertechnologie und Mikroelektronik. Mit UIC4UHFMRI wird die Toolchain vom Design bis zur Systemintegration moderner Halbleiterbauelemente an der OVGU etabliert.

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Ziel ist es den Zusammenhang zwischen einer gestörten perivaskulären Drainage und dem Auftreten von Amyloid-related Imaging Abnormalities (ARIA) bei Alzheimer-Patienten unter Amyloid-β-Antikörpertherapie zu untersuchen. Dazu wird multimodal eine Kohorte untersucht. MRT-basierte Marker für Drainage werden mit dem Blutbild korreliert um unter Berücksichtigung des Lifestyles neue Biomarker zu identifizieren. Diese Biomarker hätten das Potenzial, als nicht-invasive Marker für eine gestörte Drainage zu dienen und somit die Risikostratifizierung von Patienten zu verbessern.

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Das Gesamtziel dieses Projekts besteht darin, innerhalb des EURAMET-Netzwerks kostengünstige, quelloffene Niederfeld-MRT-Systeme zu entwickeln, inklusive Hardwarekomponenten, Datenerfassung und Bildrekonstruktion, die reproduzierbar, vollständig dokumentiert und messtechnisch charakterisiert sind.
Die spezifischen Ziele des Projekts sind:
1. Entwurf, Entwicklung und Evaluierung mobiler (<300 kg), kostengünstiger (<50 k€) und vollständig reproduzierbarer Niederfeld-MRT-Referenzsysteme (statisches Hauptfeld B0 ≈ 50 mT), die für die Bildgebung des menschlichen Kopfes und der Extremitäten geeignet sind.
2. Entwicklung modellbasierter Bildrekonstruktionsverfahren unter Verwendung der Referenzsysteme in Ziel 1.
3. Bewertung der klinischen Eignung der entwickelten Niederfeld-MRT-Referenzsysteme durch standardisierte Tests, an denen klinische Radiologen teilnehmen, um die Bildgebungsleistung an verschiedenen Standorten zu beurteilen.
4. Ermöglichung der Translation der im Rahmen des Projekts entwickelten Technologie und Messinfrastruktur durch Anbieter (z. B. akkreditierte Labors, Gerätehersteller), normenentwickelnde Organisationen (z. B. IEC TC 62/SC 62B) und Endnutzer (z. B. die klinische Gemeinschaft).

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The proposed project aims at understanding how systems level hippocampally-related functional connectivity as well as cortico-cortical microstructure changes indicative of memory engrams develop during memory consolidation. We will use a novel and unique 7T connectome MRI for humans to achieve the highest to-date possible resolution for functional and diffusion magnetic resonance imaging (MRI). This will allow imaging of the emergence of cortico-cortical connectivity and engram-related plasticity in a layer-specific manner in early and late stages of memory consolidation, thereby narrowing the gap between an animal-led and human-led understanding of memory consolidation. As neuromodulatory inputs related to more or less salient memory events are one of the most prominent drivers of the long-term stability of memories we will additionally investigate how a stronger involvement of neuromodulatory and ‘saliency-processing structures’ affects memory consolidation. Moreover, we will assess whether semantic congruency affects the time course of dynamics in the memory consolidation network or memory engram formation.

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Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neuromuscular disorder hallmarked by pyramidal cell degeneration of the motor cortex (M1). The underlying causes of sporadic ALS remain largely unknown, limiting its treatment options to supportive measures without any causal therapies. Even though many patients die within 3 to 5 years through respiratory insufficiency, individual ALS disease course and prognosis are highly variable. This is mirrored by distinct motor phenotypes, very long survival times of up to 10 years, and cessation or even reversal of disease progression in individual patients.In the presented proposal we hypothesize that a root cause of clinical ALS heterogeneity is a variable vascular supply of the motor cortex, which mitigates M1 pyramidal cell degeneration (“resistance”) or its impact on motor function (“resilience”). To address this question, we will prospectively examine a selected cohort of 20 ALS patients and 20 age- and sex-matched controls that will undergo 7 Tesla ultra-high field magnetic resonance imaging (MRI) applying angiographic (ToF-MRA) and anatomical sequences (MPRAGE). By visual rating two vascular patterns of M1 supply will be distinguished for the branches of the anterior cerebral artery (medial motor cortex) and middle cerebral artery (lateral motor cortex), respectively: a “single supply” pattern in which the M1 supply is provided by the terminal cortical arteries of one single branch only, or a “double supply” pattern, in which two branches feed the supplying terminal cortical arteries. We assume that a “double supply” pattern results in overlapping perfusion territories of both branches which mitigate M1 pyramidal cell degeneration or its impact on motor function. For quantitative analysis vessel distance mapping will be applied, which assigns each non-vessel voxel the distance to each of the examined arteries and thus consequently allows an approximation of the branches’ perfusion territories. Based upon mediation models the direct effects of the vascular supply patterns and perfusion territories on pyramidal cell degeneration (studied using M1 cortical thickness, global and body-part specific) will be assessed, as well as whether their severity mediates the influence of vascular supply patterns and perfusion territories upon motor function (global and body-part specific), both, at the time of the baseline MRI and longitudinally.Vascular patterns could serve as a new marker to explain the phenotypic variability in ALS, which might prove useful as an additional aspect for an individualized patient counseling regarding disease course and prognosis. Additionally the cerebral vasculature is potentially “dynamic” tissue, whose functionality can be modified through lifestyle and certain drugs. A “vascular approach to therapy” might lead to new avenues in the prevention and treatment of ALS.

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The Magdeburg UHF-MR Core Facility will provide 7T MRI technology and methodology that is unique in Europe. As the first centre in Europe, the Magdeburg UHF-MR Core Facility will operate two human 7T MRI systems, one state-of-the-art 7T MRI and one 7T “Connectome” MRI with unprecedented gradient performance. Users are scientists mainly from the field of basic, applied and clinical neuroscience from different institutions in Magdeburg as well as external researchers.
The main goal is to establish and provide the best possible infrastructure, measurement methods and technologies together with professional support for all imaging researchers. The project is structured into 5 work packages:
- develop and maintain cutting edge methodology
- establish methods to ensure and monitor highest data quality
- provide training and imaging support to the users
- develop and provide digital research data management tools
- establish the organizational structure and administrative procedures
The unique 7T hardware capabilities and the available unique methodological expertise and longest standing 7T MRI experience in Magdeburg form the basis for new superb research opportunities with highest level support and service for the users.

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Die Erforschung, Entwicklung und klinische Erprobung neuer MR-Techniken zur Bildgebung und Spektroskopie erfordert eine enge Zusammenarbeit zwischen SIEMENS und physikalisch-technischen und klinischen Partnern und Anwendern. SIEMENS und die UNIVERSITÄT als Anwender sind daran interessiert, im Rahmen dieses Vertrages zusammenzuarbeiten.

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Vorhabengegenstand ist der Bereich der Onkologie, mit dem Fokus auf ablative Therapien und Bildführung mittels MRT und CT mit dem Ziel der kurativen Behandlung von malignen Erkrankungen.

Die Zielsetzung besteht darin, die bildgeführten Interventionen einfacher, schneller, kostengünstiger, schonender und kurativ zu machen, sodass sie in der breiten klinischen Routine Einzug halten. Dazu wurden drei wesentliche medizintechnische Herausforderungen identifiziert, die innerhalb von vier Leit- bzw. Querschnittsthemen - iMRI Solutions, iCT Solutions, Immunoprofiling und Computational Medicine - gelöst werden sollen.

• Kurative Therapie: Heutzutage haben die Interventionen primär eine palliative Bedeutung. In Analogie zur vollständigen chirurgischen Entfernung bösartigen Gewebes (R0-Resektion) strebt STIMULATE die komplette Abtragung der Läsion (A0-Ablation) und damit die Heilung des Patienten an. Die anvisierten Zielorgane insbesondere Leber - aufgrund der komplexen Gefäßversorgung - sowie Lunge - aufgrund der Pneumothorax- bzw. Luftemboliegefahr - beinhalten erhebliche Herausforderungen bei der Planung und Durchführung bildgeführter ablativer Therapien.
• Lokale und systemische Überwachung: Die heutigen ablativen Verfahren stellen rein mechanistische Ansätze dar. Im Querschnittsthema Immunoprofiling berücksichtigtSTIMULATE erstmals - in einem translationalen Ansatz der Grundlagenforschung - die lokalen und systemischen Wechselwirkungen verschiedener lokoregionaler Therapieverfahren zur Überwachung und Prognose der kurativen A0-Therapie.
• Dedizierte Bildgebungssysteme: Gegenwärtig werden für Interventionen MRT- und CT-Geräte eingesetzt, welche für die Diagnostik optimiert wurden und nur durch behelfsmäßige Zusatzausstattungen im OP eingesetzt werden können. Mit der in STIMULATE vorhandenen Expertise im Bereich der Bildgebung wird angestrebt, in den Leitthemen iMRI-Solutions und iCT-Solutions, spezielle interventionelle Geräte zu erforschen.

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Die schwerwiegenden individuellen und gesamtgesellschaftlichen Folgen psychischer Erkrankungen sind Ausgangspunkt, und deren nachhaltige Beeinflussung das zentrale Ziel des Deutschen Zentrums für Psychische Gesundheit (DZPG). Das BMBF hat mit dem DZPG ein weiteres Gesundheitszentrum etabliert, das mit seinem Fokus auf translationale Gesundheitsforschung sicherstellen wird, dass innovative Präventions-, Diagnose- und Therapieverfahren für psychische Erkrankungen generiert und zeitnah in die Regelversorgung übersetzt werden. Darüber hinaus wird das DZPG Lösungen für inakzeptable gesellschaftliche Ungleichheiten in der Versorgung von Menschen mit psychischen Erkrankungen erarbeiten. Diese gibt es sowohl in der „horizontalen Perspektive“, so z.B. zwischen den ländlichen und städtischen Lebenswelten, als auch in „vertikalen Kontexten“ z.B. bezüglich vulnerabler Gruppen. Um diese Versorgungslücken in der Erwachsenenbevölkerung und bei Kindern und Jugendlichen zu schließen, wird das DZPG ein ambitioniertes translationales Forschungsprogramm auflegen, das die Förderung von psychischer Gesundheit und Resilienz in den Mittelpunkt stellen, die gesellschaftliche Wahrnehmung psychischer Erkrankungen verbessern und die durch psychische Erkrankungen verursachten Belastungen in den nächsten 15 Jahren reduzieren wird. Hauptpartner im DZPG sind die sechs Standorte Berlin/Potsdam, Bochum/Marburg, Halle/Jena/Magdeburg, Mannheim/Heidelberg/Ulm, München/Augsburg, Tübingen und die Repräsentanten des Zentrumsrates. Der Zentrumsrat ist der Zusammenschluss der Betroffenen und Angehörigen. Die übergreifenden Ziele des DZPG sind auch für den Standort Halle/Jena/Magdeburg maßgeblich, zudem folgende Institutionen zählen: Universitätsklinikum Jena (UKJ), Friedrich-Schiller-Universität Jena (FSU), Martin-Luther-Universität Halle-Wittenberg (MLU), Otto-von- Guericke-Universität Magdeburg (OvGU), Universitätsklinikum Magdeburg (UMMD), Leibniz-Institut für Neurobiologie Magdeburg (LIN).

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Psychiatric symptoms such as fatigue, depression and cognitive impairment are highly prevalent among long-COVID/post-COVID (LC/PC) patients. Among the mechanisms of persistent systemic and intracerebral inflammation proposed to cause LC/PC symptoms, evidence supports the perivascular inflammation hypothesis: SARS-CoV-2 damaging cerebral microvasculature and impeding brain clearance due to its destructive effects on the endothelium. Preliminary results revealed a significant correlation between enlarged perivascular spaces (EPVS) in the basal and symptoms of fatigue in LC/PC patients. We hypothesize that EPVS severity could be dynamically associated with clinical symptom development in LC/PC and will study EPVS dynamics over time to test for a mediating role of EPVS load on psychiatric and cognitive symptoms.

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Abstrakt

An accessory kit is provided for interventional procedures using a magnetic resonance imaging scanner. The accessory kit includes a patient support and an electrical connection adapter. The patient support has a first end proximal and a second end distal to the scanner. The distal end is configured to create a space to accommodate a clinician, such as narrowing of the distal end or at least one cutout on a side of the distal end. The electrical connection adapter interfaces with the scanner and a scanner table. The accessory kit is configured so that when the proximal end is extended into the scanner bore, the distal end extends outside the bore. The narrowed width and/or cutout(s) of the exposed distal end and the extended gap between the scanner and scanner table create space on at least one side of the patient support that a clinician may use to access a patient.

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Die Amyotrophe Lateralsklerose (ALS) ist eine rasch progrediente neuromuskuläre Erkrankung mit Degeneration der Pyramidenzellen des Motorkortex‘ (M1). Die Ursache der sporadischen Form der ALS ist unvollständig geklärt; die Behandlung der Erkrankung rein supportiv, kausale Therapieansätze fehlen. Obwohl viele der betroffenen Patienten innerhalb von 3 bis 5 Jahren nach Diagnosestellung an einer Insuffizienz der Atemmuskulatur versterben, sind Krankheitsverlauf und Prognose im Einzelfall äußerst heterogen. Dieses wird anhand individueller motorischer Phänotypen, langer Krankheitsverläufe oder einer möglichen Regredienz motorischer Funktionsverluste deutlich. Im vorgelegten Antrag hypothetisieren wir, dass dieser Heterogenität eine variable Gefäßversorgung des Motorkortex‘ zugrunde liegt, die einer M1-Pyramidenzelldegeneration ("resistance") oder deren motorischen Folgeerscheinungen ("resilience") entgegenwirkt. Zur Beantwortung der Fragestellung wird prospektiv eine selektierte ALS-Kohorte von 20 Patienten sowie 20 alters- und geschlechtsangepasste Kontrollprobanden mittels 7 Tesla Ultra-Hochfeld-Magnetresonanztomographie (MRT) unter Verwendung einer Angiographie (ToF-MRA) und anatomischer Sequenzen (MPRAGE) untersucht. Visuell werden zwei vaskuläre M1-Muster, jeweils separat für die Äste der A. cerebri anterior (medialer Motorkortex) und die der A. cerebri media (lateraler Motorkortex) unterschieden: singulär, d.h. eine M1-Versorgung durch die terminalen kortikalen kleinen Arterien eines Astes, oder dual, d.h. durch die terminalen kortikalen kleinen Arterien von zwei Ästen. Es wird angenommen, dass ein duales vaskuläres Muster aufgrund überlappender Perfusionsterritorien beider Äste einer Pyramidenzelldegeneration oder deren motorischen Folgeerscheinungen entgegenwirkt. Zur quantitativen Analyse wird das "vessel distance mapping" angewandt, welches jedem Voxel die Distanz zu den untersuchten Arterien zuordnet, woraus sich eine Approximation der Perfusionsterritorien ableiten lässt. Anhand von Mediationsmodellen werden direkte Effekte von vaskulärem Muster und Perfusionsterritorien auf die Pyramidenzelldegeneration (erfasst anhand der M1-Kortexdicke) untersucht, und, inwiefern deren Schwere den Einfluss von vaskulärem Muster und Perfusionsterritorien auf die motorische Funktion (global und körperteilspezifisch) zum Zeitpunkt des Einschluss-MRTs und im Langzeitverlauf vermittelt. Vaskuläre Muster könnten als neue Variable die phänotypische Variabilität der ALS erklären helfen, die auch translational im klinischen Alltag als zusätzlicher Aspekt für eine individualisierte Patientenberatung bezüglich Krankheitsverlauf und Prognose heranziehbar wäre. Die zerebrale Vaskulatur stellt potentiell modifizierbares Gewebe dar, dessen Funktionalität sowohl medikamentös als auch anhand von Lebensführung beeinflusst werden kann. Ein "vaskulärer Therapieansatz" könnte in dem Sinne zu vollkommen neuen Strategien in der Prävention und Behandlung der ALS führen.

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Research areas
Biomedical Technology and Medical Physics (205-32)
Biomedical System Technology (407-06)

Due to the limited accessibility of the bulk material to direct detection methods, often only integral flow quantities can be measured at the inlet and outlet of packed bed reactors. The exact understanding of the processes inside these technical systems is, thus, just as difficult as the system design with regard to energy efficiency and product quality. Furthermore, predictions from simulations cannot be experimentally validated in detail. Therefore, in project A2 the three-dimensional (3D) velocity field of the gas flow will be first measured in the reference configuration of the CRC/TRR with spherical and complex shaped particles by means of hyperpolarised phase contrast magnetic resonance imaging (pc-MRI). Three-dimensional, temporally and spatially resolved flow maps of the entire gas volume will be generated. These flow field data are essential and form the basis for the further understanding of the homogeneous and heterogeneous chemical reaction rates in particle beds. Sensors or tracer particles, which in turn can perturb the flow and particle movement, are not required. Optical access is also not necessary and arbitrary geometries are possible. The high flexibility of pc-MRI allows adaptations of the measurement to the requirements, e.g. regarding the sample volume (up to about 40 x 40 x 40 cm in commercial MRI) and the spatial (approx. 1 millimetre) or temporal resolution (approx. 1/10 second). With established MRI methods, usually only liquids can be detected due to their favourable physical properties with regards to generation of magnetisation (also called spin polarisation) and its life-time (relaxation properties). In this project, the transition to gaseous media is made possible by the application of highly innovative hyperpolarisation techniques. With this, the comprehensive three-dimensional, quantitative measurement of gas flow fields in complex geometries of non-transparent particle beds will be possible for the first time. Therefore, in addition to hyperpolarisation of the gas, MRI flow measurement methods for hyperpolarised magnetisation must be established. In addition, the development of materials and measurement setups is required that support the use of hyperpolarised gases without interference with the high spin polarisation. A2 will, therefore, build a continuous flow Xenon hyperpolariser with sufficient flow and polarisation level for fast and accurate MRI detection of gas (WP 1), a Xe-coil for Xe-MRI (WP 2), select and characterise proper materials for building an MR-compatible reference experiment (WP 3), extend a table to MR system for Xe-capability (WP 4), develop 3D pc-MRI flow measurement method for the application in hyperpolarised gas systems (WP 5) and measure and process flow data from the reference configuration (WP 6) to be provided to the simulation projects and to be compared to the other experimental methodology.

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Ein 7 Tesla Magnetresonanztomograph (MRT) mit einzigartigem Leistungsvermögen, welches weit über das vorhandene 7 Tesla MRT hinausgeht, wird als Forschungsinfrastruktur in Magdeburg mit Hilfe des Forschungsprogrammes Sachsen-Anhalt Wissenschaft/Infrastruktur etabliert. Diese Forschungsinfrastruktur kombiniert die ultra-hohe Magnetfeldstärke und damit Sensitivität von 7 Tesla MRT mit den stärksten Bildgebungsgradienten ("Connectome Gradienten"), welche die Informationskodierung bewirken. Die Gradienten werden mindestens die dreifache Stärke und doppelte Geschwindigkeit des vorhandenen Systems erreichen. Dies ist die konsequente Fortführung und Erweiterung der Bildgebungsinfrastruktur für die Neurowissenschaften und sichert Magdeburg eine Führungsposition in diesem Forschungsfeld.

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Im Teilprojekt B06 untersuchen wir, welche funktionellen Netzwerke im Gehirn die Festigung (Konsolidierung) neu gelernter Informationen regulieren. Wir wollen untersuchen, wie die Dopamin-Freisetzung in der Ruhephase nach dem Lernen mit der langfristigen Gedächtniskonsolidierung und deren Abnahme im Alter in Verbindung steht. Um diese Ziele erreichen zu können, werden wir multi-modale funktionelle Magnetresonanztomographie (fMRI) und molekulare Bildgebung (Positronen-Emissions-Tomographie - PET) mit Hilfe des in Magdeburg neu verfügbaren simultanen MRT und -PET Gerätes nutzen. Wir verbinden die experimentellen Untersuchungen mit computationaler Modellierung der Hirnaktivitätsdaten um die Netzwerkprozesse im Gehirn besser zu verstehen.

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Das Upgrade ermöglicht den vorhandenen 7 Tesla Magnetresonanztomographen der OVGU, auf den aktuellen Stand der Technik der 7 Tesla Ultrahochfeld-MRT zu bringen. Das Upgrade erlaubt die sichere Nutzung von Mehrkanal-Anregungsverfahren (pTx), die zu verbesserter Bildqualität in Regionen des Gehirns führt, die mit bisheriger Technik nicht homogen angeregt werden können (vor allem im Kleinhirn und im unteren Bereich des Temporallappens). Hierzu ist neben dem Hard- und Software-Upgrade des MRT Gerätes, zudem eine neue Mehrkanal-Sendespule notwendig. Das Hardware-Upgrade ist Voraussetzung für die Verwendung der neuesten Software Generation (VE12) und damit der Nutzung von Neuentwicklungen von MRT Mess-Sequenzen, insbesondere der Multiband-Technik. Hier erlauben neuartige Verfahren der Aufnahme eine größeren Anzahl Schichten bei gleicher Messzeit, die auf die im Upgrade enthaltenen leistungsstärkeren Rechner und Steuerungselektronik angewiesen sind. Durch die Maßnahme wird die OVGU somit in die Lage versetzt, auch für die nächsten Jahre voll kompetitive Drittmittelforschung im Rahmen von EU, BMBF und DFG Projekten, wie dem aktuellen SFB 1436 durchführen zu können. Auch für die Exzellenzinitiative der OVGU bildet die Bildgebungsinfrastruktur eine wichtige Säule.

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Die Integrität und Funktion des Gehirns ist auf den Zu- und den Abfluss von Blut durch das arterielle bzw. venöse Gefäßsystem angewiesen. Subkortikale Strukturen, die an motorischen, sensorischen, kognitiven und verhaltensbezogenen Aufgaben beteiligt sind, werden von den großen Hirnarterien durchströmt. Die Perfusionsterritorien dieser großen Arterien sind zwischen Probanden räumlich variabel. Diese Variabilität beeinflusst die Organisation der kleinen, perforierenden Arterien. Wir vermuten, dass sich diese Variabilität der subkortikalen Perfusionsterritorien von der arteriellen Seite ausgehend durch das Kapillarbett in die Organisation der subkortikalen Venen propagiert. Daher nehmen wir an, dass subkortikale arterielle und venöse Gefäße voneinander abhängig sind und dass unterschiedliche Gefäßmuster existieren. Wenn sich also die Trajektorie eines einzelnen, subkortikalen Gefäßes verändert, könnte dies zu Veränderungen im umgebenden arteriellen und venösen Netzwerk führen, um ein bestimmtes Muster lokaler Gefäßabstände aufrechtzuerhalten. Diese vermutete, wechselseitige Abhängigkeit der arteriell-venösen Muster ist nach unserem besten Wissen bisher nicht umfassend untersucht worden. Um diese Hypothese am lebenden Menschen nicht invasiv zu bestätigen, wurden folgende Ziele identifiziert:(1) Verwendung von Ultra-Hochfeld-MRT und prospektiver Bewegungskorrektur, um die erforderlichen hohen Auflösungen (Voxelgröße < 0,4 mm) zur Darstellung der perforierenden Arterien und Venen zu erreichen(2) Segmentierung des Gefäßsystems mit Hilfe eines Vesselness-Filters und Verwendung einer Entfernungstransformation, um Gefäßdistanzkarten zu berechnen.(3) Finden von gemeinsamen, subkortikalen arteriell-venösen Mustern durch unüberwachtes Clustering.(4) Validierung jedes Verarbeitungsschrittes durch ExpertenDurch Erreichen dieser Ziele wird eine neuartige, vollautomatische Technik zur Analyse von Gefäßdistanzmustern etabliert. Darüber hinaus könnte der Nachweis der Interdependenz des arteriellen und venösen Gefäßsystems einen Einfluss auf die Bildgebung, Diagnose und Behandlung kleiner Gefäße im Allgemeinen haben, da eine gemeinsame Analyse vorteilhafter wäre als die Fokussierung auf eine einzelne Seite des Gefäßsystems. Da die vaskuläre Komponente neurodegenerativer Erkrankungen und des Alterns spezifische Gefäßmusterverläufe induzieren könnte, könnte der vorgeschlagene Ansatz als neuer Biomarker in zukünftigen, longitudinalen Studien eingesetzt werden.

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In this ABINEP sup-project high field MRI and MR-PET will be further developed to detect and visualize hippocampal structure and sub-structures. These methods will be applied in clinical studies with subjects  in prodromal (non-symptomatic) stages and early stages of dementia.

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Medical imaging encompasses a versatile toolkit of methods to generate anatomical images of a single organ or even the entire patient for diagnostic and therapeutic purposes. Radiation-based imaging technologies are of inestimable importance and hence performed in daily clinical practice.
Electromagnetic radiation may, however, cause undesirable side effects. Consequently, methods allowing for dose reduction are expected to prospectively come into focus. This may specifically hold for patients, who need to be scanned periodically for therapy and/or health progress monitoring.
Instead of performing an entire scan per session, prior knowledge derived from preexisting multimodal image data sourcing, anatomical atlases, as well as mathematical models may be integrated - the latter reducing radiation dose and scan duration thus finally saving health expenditures.
In order to do so, available images and data need to be updated based on newly acquired subsampled data.
The application of prior knowledge may furthermore advance minimally invasive interventions by means of intraoperative image acquisition. Within this context, consecutive scans usually show a high degree of similarity while differing only in probe position and respiratory organ motion. Lower radiation loads vs. significant increases in image frame rate may result when spotting those similiarities based on formerly acquired image information.
The integration of prior knowledge therefore holds a great potential for improving contemporary interventional procedures - especially in the field of interventional magnetic resonance imaging (IMRI).
Graduates in medical imaging science, medical engineering or engineering, computer, and natural science will have the opportunity to work with high-tech diagnostic devices such as x-ray examination and computed tomography (CT), state-of-the-art single-photon emission computed tomography (SPECT) and positron emission tomography (PET) within a structured 4-year/48-month PhD track.

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This sub-project aims at the reconstruction of dynamic time series from fast acquisitions.

Typically, these fast acquisitions are of lower quality (e.g. wrt resolution, contrast, or artefacts) compared to slower scans with higher resolution, the latter being acquired for the purpose of planning. At the same time we know that the object is mainly left unchanged apart from potential non-linear deformations and the presence of an interventional tool (e.g. a needle) with its position being precisely known.

Consequently, a lot is known about the object expecting this prior knowledge to enable the reconstruction of dynamic high resolution and high contrast images.
Therefore, different approaches may be applied including image-based matching and deformation, model-based reconstruction using prior knowledge to support regularisation, or even machine learning methods.

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The GUFI network was founded at the end of 2013 as DFG-funded Core Facility. The initial project duration was three years. The overall goal of GUFI is to facilitate and harmonize the access to German Ultra High Field (UHF) sites. GUFI has made important contributions to addressing these challenges and has identified several new areas of common interest to all German UHF sites. A number of unprecedented milestones have been achieved in building a national UHF Magnetic Resonance (MR) community including establishment of a common presentation and access portal for all UHF MR sites; initiation of regular QA; consensus on access procedures, implant handling and RF coil testing; and regular structured communication between all UHF sites. In a second funding phase, starting 2017, the following goals will be pursued:

• Establishment of an online platform for MR safety training including examination questions to verify attainment of training goals.
• Continuation and extension of establishment of procedures for safe examinations of subjects with implants. Continuation and refinement of QA activities.
• Formulation and publication of White Papers.
• Annual workshops with participation from all GUFI sites to foster communication.
• Planning of first multicenter UHF trials.
• Maintenance and extension of the online web-based communications platform.
• Coordination activities with other international initiatives such as UK7T and Euro-Bioimaging.
• Preparation of access procedures for the infrastructure to be established at National Biomedical Imaging Facilities in Jülich and Heidelberg that have been applied for as part of the National Roadmap for Research Infrastructures of the German Federal Ministry of Education and Research (BMBF).

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MR imaging is currently optimized for the examination of adult patients. The examination of newborn and small babies is a challenge for radiology and neonatology (technically and logistically). The startup company Neoscan Solutions is developing a dedicated MR-system for neonatal diagnosis. This system can be installed within a neonatology department due its small footprint (size and weight) and cryogen-free operation. Together with this company and within this cooperation project, we develop the radio-frequency transmit and receive system for this MR operating at the clinically established 1.5T magnetic field strength. This includes transmit and receive RF-coils for the examination of small children but also their implementation into incubators. In addition, patient positioning and patient support will be developed.

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The acquisition of MR images might run considerably slow due to the one-dimensional character of the signal and the need to consecutively measure many data points for a single image. Classically, an image cannot be uniquely reconstructed if the number of measured data points deceeds the number of points in the image.

In this project, prior knowledge derived from other sources than the MR acquisition itself will be used to uniquely reconstruct MR images from less-than-complete measurement data, particularly aiming at faster acquisition in moving organs. Therefore, (prior) knowledge such as information on the position of interventional instruments or the subject's breathing motion (deforming abdominal organs whereas not entirely changing the object itself) will be exploited and incorporated into mathematical models - the latter describing these objects and in turn being parameterised based on measurement data.

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MR imaging is currently optimized for the examination of adult patients. The examination of newborn and small babies is a challenge for radiology and neonatology (technically and logistically). The startup company Neoscan Solutions is developing a dedicated MR-system for neonatal diagnosis. This system can be installed within a neonatology department due its small footprint (size and weight) and cryogen-free operation. Together with this company and within this cooperation project, we develop the gradient system for this MR operating at the clinically established 1.5T magnetic field strength. This includes control, supervision and optimization of the gradient sub-system.

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Animals exploring unknown environments face problems at multiple time-scales: in the short run, they must solve problems of pattern recognition, scene understanding, decision making and action selection while, in the long run, they must also develop strategies for building an internal representation of the environment as a basis for causal understanding / generative modelling.  From a computational point of view, the main difficulty is representing and learning the rich temporal structures and conditionalities that encapsulate the co-dependencies between environment and actions.
Current behavioural tasks – e.g., sequence learning, sequential reaction time tasks, conditional associative learning – barely touch upon these difficult issues.  To address this more directly, we will study human learning of arbitrary sensorimotor mappings in the presence of rich temporal context, as well as the neural correlates of such learning in networks involving the hippocampus / medial temporal lobe.  Specifically, we hypothesize that rich, quasi-naturalistic, temporal context will (i) dramatically facilitate learning by means of (ii) engaging hippocampus and medial temporal lobe structures.
To investigate these two hypotheses, we will monitor human learning of visuomotor associations in temporal contexts of different complexity.  To this end, we will develop novel, quasi-naturalistic, temporal sequences with statistical structure over several time-scales.  To investigate neural correlates, we will study functional correlations of voxel-based BOLD activity in pairs of (small) brain areas – e.g., hippocampus and inferior temporal cortex – relying on 3T or 7T high-resolution MRI.  Recent work, by ourselves and others, shows that voxel-level functional correlations can delineate with high fidelity the cortical circuits engaged in different task states.

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Background
Undersampling MR images leads to an insufficient amount of data for conventional reconstruction techniques, making it an ill posed inverse problem. Deep neural networks provide promising solutions to the problem, but lack explainability.

Objective
MRI acceleration, especially golden angle radial sampling, in the process making real time MRI possible.

Methods
>> Utilizing and improving data-driven neural network approaches and their analysis

Results
>> Up-to-date deep learning reconstruction methods for undersampled radial MR signal data in image and signal domain with competitive results in that field of research

Conclusions
Current methods still mark the starting point since they are still missing key points like holoporphic activation functions for computing complex gradients throughout neural nets.

Orignality
>> Problem specific methods that are tailored to the underlying complex valued MR problem

Keywords
>> MRI, undersampling, reconstruction, deep learning, unblackboxing

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The integrity and function of the brain rely on the supply and draining of blood through the arterial and venous vasculature, respectively. Subcortical structures, involved in motor, sensory, cognitive and behavioral tasks, are perfused by the major cerebral arteries. The perfusion territories of these large arteries are spatially variable between subjects. This variability influences the organization of small, perforating arteries. We hypothesize that this variability in subcortical perfusion territories is propagated from the arterial side through the capillary bed into the organization of subcortical veins. Thus, we suspect that subcortical arterial and venous vasculatures are interdependent and that distinct vessel patterns exist. Therefore, if the trajectory of an individual, subcortical vessel is altered, this could induce changes within its surrounding arterial and venous network to maintain a specific pattern of local vessel-vessel-distances. To our best knowledge, this hypothesized interdependency of the arterial-venous patterns has not been studied comprehensively to date. To validate non-invasively this hypothesis in living humans, the following objectives have been identified:

1. Use ultra-high field MRI and prospective motion correction to achieve the required high resolutions (voxel size < 0.4mm) to depict the perforating arteries and veins
2. Segment the vasculature using a vesselness filter and apply distance transform to compute vascular distance maps
3. Find common, subcortical arterial-venous patterns using unsupervised clustering
4. Validate each processing step thoroughly by experts

By addressing these objectives, a novel, fully automatic technique to analyze vascular distance patterns will be established. Further, proving the interdependency of the arterial and venous vasculature could have an impact on small vessel imaging, diagnose, and treatment in general, as an interdependency might render a joint assessment more promising that focusing on a single side of the vasculature. As the vascular component of neurodegenerative diseases and aging could induce specific vessel-vessel-pattern progressions, the proposed approach could be used as a new biomarker in future, longitudinal studies.

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It is known from animal work that most mechanisms limiting neural resources manifest at the level of brain microstructure and influence brain functions at different hierarchical levels, such as brain macrostructure, neuronal networks, and behavioural phenotypes. Current research on neural resources in humans, however, often lacks a mechanistic level of explanation due to missing technology and/or methodological expertise needed to describe neuronal changes at the meso-scale (i.e. at the level of cortical layers or neuronal ensembles). This hinders knowledge transfer from mechanistic insights at the micro-scale gained in animal research to macro-scale human brain models and interventions. The CRC initiative has the overall goal to systematically investigate neural resources at the micro-, meso-, and macro-scale by taking an interdisciplinary and multi-scale approach and to link changes in the functional and structural architecture of cortical and subcortical micro-circuits to behavioural performance and cognitive interventions. Technological advancements in meso-scale brain imaging, meso-scale data modelling, and multi-modal and multi-scale data interaction can bridge this gap. The aim of Z02 is to develop and test novel technologies using ultra-high resolution 7 Tesla magnetic resonance imaging (7T MRI) for wider applications in human subjects and primates and to provide them to the researchers of the CRC projects by ensuring (i) usage of appropriate and state-of-the-art MR-sequences that offer reproducible and optimised data quality and (ii) computational tools and analysis pipelines for multi-modal and multi-scale data modelling within and across individuals. Z02 has the overarching goal of modelling the human cortex in three dimensions, that is, both in plane at the cortical surface (dimensions 1&2) and in cortical depth (dimension 3, cf. Kuehn & Sereno 2018, Fig. 1). This approach extends the frequently applied localisation of function in cortical regions, e.g. Brodmann areas, or more advanced and ambitious columnar mapping, to a novel level of detail relevant for cognitive processes (e.g., Larkum et al. 2018). This will allow the CRC projects to target research questions on neural resources in a novel yet undiscovered dimension, while at the same time enabling Magdeburg to maintain its leading position for human brain imaging in Europe.

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The goal of project A07 is to delineate the functional network level regulation of dopamine release in response to novelty and action for reward and to investigate the relationship between dopamine release and memory consolidation in young and old adults. To achieve these goals, we will continue our successfully established multimodal approach of combining imaging at 3T, 7T and PET. We will achieve a direct integration of fMRI and dopamine release by using a new, truly simultaneous MR-PET facility in Magdeburg. We will also determine whether a norardrenergic brain region, the locus coeruleus, may be a bottleneck for dopamine-release in the hippocampus.

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Project A12 addresses the role of the habenula (Hb) in motivated behaviour of humans. The Hb is an important relay on a major descending pathway from the forebrain to the brain stem with predominantly inhibitory influence on monoaminergic nuclei, thereby controlling release of dopamine and serotonin to the forebrain. The project aims at understanding the contribution of the Hb to active and passive avoidance and to learning from aversive events. This comprises studying habenular activity, its structural and functional embedding in pallido-habenulo-mesencephalo-striatal networks, and its neurochemical interactions. To this end, high-resolution structural, diffusion-weighted and functional MRI, pharmacological challenges, and in-vivo receptor density mapping using positron emission tomography will be performed in healthy volunteers. Understanding habenular functions is important not only for fundamental neurosciences but also for clinical neuropsychiatry, because dysfunction of the Hb has been suggested to contribute to the pathophysiology of psychiatric disorders, such as affective disorders and addiction. Therefore, we will search for volume and connectivity aberrations of the Hb in patients with addiction.

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Die Forschungsgruppe Interventionelle MR-Bildgebung innerhalb des Forschungscampus STIMULATE erforscht gemeinsam zwischen SIEMENS und der OVGU spezielle Protokolle (Sequenzen) für den Einsatz der MRT-Bildgebung in der Intervention, und testet diese auf ihr Verbesserungspotenzial. Die primären Ziele sind Echtzeitfähigkeit der Bildgebung bei hohem Tumorkontrast und gemeinsam mit dem weiteren Partner Metria Inc. eine automatische Verfolgung des OP-Instruments zur permanenten Visualisierung. Mittelfristig sollen neue Kontrastmechanismen wie Gewebeelastizität oder Leitfähigkeit komplementäre Informationen zur Tumoridentifikation und -visualisierung liefern.

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In this project, funded by the National Institute of Health, methods for prospective motion corrected MRI are developed. These methods enable examination of motion-prone subjects without the need for rescanning and with improved image quality.

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Single-shot echo-planar imaging (EPI) is a well-established technique with moderate spatial resolution but high imaging efficiency. It is widely adapted in various brain imaging applications such as functional MRI (fMRI), perfusion weighted MRI, and diffusion tensor imaging (DTI). EPI, however, is very sensitive to inhomogeneities induced by the main magnetic field as well as magnetic susceptibility differences in the object. These effects cause phase disturbances due to the low effective bandwidth in the phase encoding direction, leading to distortions of the image geometry and signal intensity. Moreover, in EPI-based diffusion weighted imaging (DWI), these distortions additionally vary according to the diffusion encoding direction due to eddy currents induced by the rapid and large changes of the magnetic field associated with the ramp-up and ramp-down of these encoding gradients. Since field inhomogeneities are directly proportional to the strength of the main magnetic field, these distortions are increased at high field strengths of 3 Tesla and above, and become a significant obstacle for EPI-based applications at ultra high field (UHF) such as 7T. In this project, we propose the development, implementation and testing of an improved approach to measure, characterise, and compensate strong EPI distortions. The development and evaluation will be performed at 7T in phantoms and human subjects. The project covers an implementation of the improved method for fMRI applications and its further extension for reliable DTI applications. Significantly improved stability and imaging properties of EPI allowing more sensitive experimental results and higher positional accuracy are predicted for the proposed method. This will be achieved without prolonged scan times since all data directly enter the DTI results.

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Innerhalb des Unterauftrages #1 zwischen KinetiCor und der OVGU werden Methoden, welche in meiner Abteilung (BMMR) an der OVGU entwickelt wurden, an einen neuen Standort transferiert und erweitert. Die Methoden wurden auf einem 7T MRT des Baujahres 2004 entwickelt und werden für Geräte neuester Bauart und unterschiedlicher Magnetfeldstärke weiterentwickelt. Dies bedingt Modifikationen und Anpassungen der Methoden inklusive neuer Entwicklungen zur Ankopplung und Kalibrierung der Geräte sowie Messmethoden. Die Bewegungskorrektur ist ein wesentlicher Aspekt unseres aktuellen Forschungsportfolios und daher sind diese gemeinsamen Forschungsarbeiten mit dem Partner KinetiCor sowie der Universität Freiburg, welche ebenfalls bilateraler Partner von KinetiCor ist, von wesentlichem Interesse für unsere Forschung, welche hiervon ebenfalls profitiert. Ich ordne die Arbeiten daher als Anwendungsforschung mit dem Ziel des Erkenntnisgewinns sowie Erweiterung der möglichen Anwendungen auf weitere Feldstärken und Gerätekonfigurationen ein.

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Within the past few years, seven centers for human ultra-high-field (UHF) magnetic resonance (MR) imaging have been set up in Germany. To make this expensive and highly complex technology accessible to a larger number of researchers, organizational cooperation of the UHF MR centers is crucial. To achieve this goal, all German UHF centers have decided to establish a national network called German Ultrahigh Field Imaging (GUFI), which will be coordinated by the centers in Essen and Magdeburg. Within the proposed project, vital organizational structures will be created at both the administrative and technical levels. In particular, communication between the centers and external users will be facilitated via a web portal. On the technical level, the project involves the exchange of latest imaging protocols and in particular the development of new approaches to ensure common qualitystandards for the obtained image and spectral data, optimized for the challenges of UHF MR systems, so that external users can be assured of ideal conditions and so that measurements on different UHF MR systems can be compared.

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Multivariate pattern analysis (MVPA) of functional magnetic resonance data has recently been widely used inthe neurosciences. MVPA promises to yield information about brain function with high spatial resolution.Recently, however, conflicting results were published concerning the information carried by functionalmagnetic resonance data at different spatial scales and their contribution to classification analyses. In thepresent project, we intend to investigate to what degree the high spatial resolution and sensitivity yielded athigh magnetic field strength contributes to an improved classification of functional activation patterns. To thisend we vary field strength (3T and 7T), spatial resolution and sensitivity and investigate their influence understimulation conditions that create neuronal excitation patterns in the sub-millimeter versus multiple-millimeterscale. The overall goal of the project is the characterization of factors influencing multivariate pattern analysisof functional magnetic resonance data and, subsequently, the optimization of future experimental designsusing MVPA.

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The High field Magnetic Resonance (HiMR) Initial Training Network aims to train the future leaders of academic and industrial research in the fundamental science and novel applications of ultra-high field (UHF) in vivo magnetic resonance (MR), in order to address an increasing and currently unmet demand from academia and industry for such specialists. The highly complex and multi-faceted nature of UHF MR means that excellent training can only be provided by immersing ESRs in an environment that integrates different research areas, sectors and groups.

The HiMR ITN is centred on a cutting edge, multidisciplinary research program that exploits the complementarities of the participants. This research programme is organised into four themes each focused on a crucial area of development of UHF. The first focuses on improved structural imaging, advancing our understanding of the origins of contrast in MRI scans and developing non-invasive biomarkers for multiple sclerosis. The second theme is centred upon exploiting UHF to develop ultra-high resolution functional MRI (fMRI) which will be very important in basic neuroscience research. It also aims to make fMRI more quantitative, thus encouraging its uptake in the clinic. The third theme aims to exploit the enhanced sensitivity of MR spectroscopy (MRS) at UHF in developing highly specific biomarkers. The final theme will develop novel hardware for both research and in the clinic, and methods of monitoring and correcting motion which limits in-vivo MR resolution. Finally the HiMR ITN will provide a unique opportunity to measure safety outcomes over a large group of workers.

The interdisciplinary and intersectoral training program will provide a platform for training ESRs to become specialists in UHF MR, whilst also furnishing them with experience of a broad range of work environments, experimental techniques and theoretical knowledge relevant to the full range of in vivo MR.

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Single-shot echo-planar imaging (EPI) is a well-established technique with moderate spatial resolution but high imaging efficiency. It is widely adapted in various brain imaging applications such as functional MRI (fMRI), perfusion weighted MRI, and diffusion tensor imaging (DTI). EPI, however, is very sensitive to inhomogeneities induced by the main magnetic field as well as magnetic susceptibility differences in the object. These effects cause phase disturbances due to the low effective bandwidth in the phase encoding direction, leading to distortions of the image geometry and signal intensity. Moreover, in EPI-based diffusion weighted imaging (DWI), these distortions additionally vary according to the diffusion encoding direction due to eddy currents induced by the rapid and large changes of the magnetic field associated with the ramp-up and ramp-down of these encoding gradients. Since field inhomogeneities are directly proportional to the strength of the main magnetic field, these distortions are increased at high field strengths of 3 Tesla and above, and become a significant obstacle for EPI-based applications at ultra high field (UHF) such as 7T. In this project, we propose the development, implementation and testing of an improved approach to measure, characterise, and compensate strong EPI distortions. The development and evaluation will be performed at 7T in phantoms and human subjects. The project covers an implementation of the improved method for fMRI applications and its further extension for reliable DTI applications. Significantly improved stability and imaging properties of EPI allowing more sensitive experimental results and higher positional accuracy are predicted for the proposed method. This will be achieved without prolonged scan times since all data directly enter the DTI results.

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1. Vorhabenziel; REVIS will study visual system plasticity following posterior infarcts in stroke patients and animals. Specifically, we will evaluate the effects of a new non-invasive current brain stimulation method to achieve vision restoration. There are 11 Mio stroke patients worldwide that suffer from damage to lhe visual system, with 2.1 Mio new cases annually which have significant subjective impairments in everyday life. We attempt to improve brain plasticity with non-invasive alternating and direct current stimulation (applied transorbitally or transcranially) and thereby achieve clinical improvements such as better independence, return to work, improved quality of Iife (orienting, reading) and greater mobility.  2. Arbeitsplanung; We will look for signs of local and global plasticity (changes in receptive fields, activations and connectivities) in strokepatients with visual field loss before and after brain current stimulation to achieve vision restoration using functional tests, EEG, and MRI measurements.The Magdeburg part of the project will be carried out by B. Sabel, C.Gall (Inst. of Med. Psychol., project coordination) and O. Speck (Inst. of Exp. Physics), all at the University of Magdeburg. As part of the REVIS consortium, human studies will also be conducted as a joint effort with lhe partners P. Rossini (Rome) and T. Tatlisumak (Helsinki) and animal studies with V. Waleszczyk (Warsaw). Commercial collaborating partner is EBS Technologies GmbH (Kleinmachnow).

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Die Phasenkontrast MR Bildgebung ist im klinischen Einsatz ein viel genutzte Technik zur Darstellung von Flussverhältnissen in Gefäßen, z.B. im Aortenbogen oder in den intrakranialen Gefäßen. Im vorliegenden Projekt wird diese Technik gemeinsam mit dem Industriepartner Volkswagen im nicht-medizinischen Umfeld angewendet um ingenieurwissenschaftliche Fragestellungen zu beantworten.

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Für jede Intervention ist die genaue Kenntnis der Position der Instrumente relativ zur Patientenanatomie entscheidend. Zudem ist die räumliche Übereinstimmung der Voraufnahmen für die Planung des Eingriffs mit der aktuellen intraoperativen Bildgebung essentiell. Daher stehen unterschiedliche Methoden der Positionserfassung von Instrumenten im Patienten, von Patienten in Bildgebungsgeräten und physiologisch bedingter Patientenbewegung im Forschungsfokus. Auf Basis der Erkenntnisse über die unterschiedlichen Trackingmodalitäten, werden die Bildgebungsmodalitäten und die Instrumente hinsichtlich Ihrer Eignung zur Kombination mit diesen Geräten evaluiert. Über die direkte und automatische Positionierung der Bildgebung und Instrumente hinaus, können derartige externe Trackingsystem während des Eingriffs und der Bildgebung für die Erfassung physiologischer Parameter genutzt werden.

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MI - Access to Innovative TechnologiesThe objectives of WG Access to Innovative Technologies - Medical Imaging (MI) are

• To survey existing European infrastructure enabling innovative MI technologies.
• To identify the needs of the scientific community with regard to instrument developments and access to the identified innovative MI technologies including Ultra-High Field MR (UHF-MR), Novel X-ray based Phase-Contrast Imaging (PCI) and Emerging Imaging Technologies (EIT) such as combination of MR and PET, SPECT, or MEG (MR-PET, MR-SPECT, MEGMR), Electron Paramagnetic Resonance Imaging (EPRI), and Magnetic Particle Imaging (MPI).
• To search for additional emerging MI developments, which may be considered for inclusion in the forward planning of Euro-BioImaging infrastructure.
• To determine the bottlenecks for providing access to innovative MI technologies.
• To explore the feasibility of providing access to the identified innovative MI technologies by proof-of-concept studies.
• To develop a comprehensive, long-term plan for the implementation of European access to innovative MI technologies.

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In der Planung, Durchführung und Kontrolle minimal-invasiver Eingriffe werden unterschiedliche Bildgebungsmodalitäten wiederholt genutzt. Die Überlagerung der Bilddaten ist jedoch oft nur eingeschränkt oder durch nachträgliche Registrierung möglich.

In STIMULATE werden im Projekt "Bildgebung" Möglichkeiten zur weiteren Verbesserung der Modalitäten für den Einsatz zur Planung und Durchführung von bildgestützten minimal-invasiven Eingriffen in Machbarkeitsstudien evaluiert. Hierbei werden innovative Ansätze für die Darstellung mittels 3D-roboterbasierter Angiographie und der Kernspintomographie, neuartige Photonendetektoren und intravaskuläre Bildgebung untersucht, um langfristige Forschungsprogramme in der Hauptphase zu definieren. Im Fokus stehen z.B. Möglichkeiten zur Verbesserung der Bildqualität, zur Verkürzung der Messzeit und Reduktion der Patientendosis sowie zur Erhöhung der Sicherheit des Arbeitsbereiches und der Nutzerfreundlichkeit.

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Advances in Magnetic Resonance (MR) neuroimaging tools have greatly contributed to recent developments in the understanding of biological processes in psychiatric diseases such as Major Depressive Disorder. Using functional MRI (fMRI), a subset of specific brain regions that experience characteristic alterations of brain responses during well-delineated psychological conditions have been identified. While some consistencies were found with structural MR assessments and postmortem studies, the molecular basis of these alterations is largely unknown. This is due, primarily, to the inherent technical difficulties encountered in the leading non-invasive imaging technique available: Magnetic Resonance Spectroscopy (MRS). In animal models, and postmortem studies in humans, deficiencies in specific cellular targets within the glutamatergic system, e.g. the glial glutamate re-uptake from the synaptic cleft and its subsequent conversion to glutamine, have been reported. Such glutamatergic origins of dysfunction are further supported by pharmacological evidence of the beneficial effects of glutamate-modulating agents in depression, suggesting treatment-related changes of metabolite levels in a subset of regions. Further systematic investigations in psychiatric neuroimaging studies are primarily hindered by technical limitations resulting in an inability to discern glutamate and glutamine in MR-spectra at field strengths of up to 3 Tesla. Recent single-voxel solutions to circumvent the lack of sufficient line separation resulted in relatively large voxels that had to be measured for up to 20 minutes to obtain reliable metabolite separation. Studies to date were thus unable to systematically investigate brain regions with adequate resolution given the functional heterogeneity of key brain regions known from functional imaging studies. The long acquisition duration for each location further prevented investigations of regional specificity via assessments of a greater numbers of regions. Our project thus aims to develop an optimized MRS method to accomplish these goals using a STEAM-based sequence at ultra high field strength of 7 Tesla.

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The major goals of this project are to develop new technology to overcome the limitations of ultra high field imaging in humans (higher than 7 Tesla). The project consortium consists of University Freiburg, Siemens Medical Systems, and Bruker Biospin. The University Magdeburg is sub-contractor to the University Freiburg and Siemens Medical Systems and involved in the development of methods for real-time scanner control and parallel transmission.

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The project aims at linking microscopic water-macromolecule exchange processes with the macroscopic MRI phase contrast detected at 7-T in the human brain. As the basis for further development, we will first characterize the WME interaction under carefully controlled experimental conditions with high resolution NMR spectroscopy.Different macromolecule parameters, such as molecular size, molecular weight, temperature, viscosity, pH, ionic strength etc. will be studied systematically. This will be extended to structural factors (protein sub-domains, ?-helix and ?-sheet content, etc), that are closely related to protein conformation. Protein cleavage and 2D/3D NMR spectroscopy will be used to study the correlation between structural factors and WME.To extend the WME model for in vivo quantification, a good understanding of the macromolecule distributions in brain tissues and their contributions to the phase contrast is required. This will be achieved by systematic macromolecule determination in tissue extracts from different mouse brain regions (cortex, cerebellum, striatum, hippocampus, thalamus, etc) and different cell components, including cytosolic, myelin, cell membrane, and synaptic fractions. The macromolecule distribution will be correlated with in vivo phase imaging and magnetization transfer studies of the same mouse to quantitatively determine the macromolecule contribution to the phase contrast. This will be further extended with an EAE (experimental autoimmune encephalomyelitis) mouse model to study multiple sclerosis. A detailed understanding of the WME and the in vivo phase contrast from animal studies will form the basis for quantitative phase imaging studies in MS patients.The project addresses the following main scientific questions: i. How do macromolecules interact with water? ii. Is it possible to observe dynamic protein conformation changes using WME? iii. What is the in vivo macromolecule distribution and its contribution to the WME frequency shift as determined by MR phase contrast imaging? iv. How can the WME model be used to study quantitatively in vivo pathologies involving macromolecule alternation? This project is based on a four-partner-network between the Department of Biomedical Magnetic Resonance, the Institute for Chemistry, the Dept. Neurology II, Otto-von-Guericke University, and the Institute for Neurobiology (LIN).

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Die Bildqualität in der Magnetresonanztomographie wird u.a. durch die Stärke und Homogenität des messbaren NMR-Signals bestimmt. Mit der Einführung des 7T MRT hat hier eine neue Ära begonnen, mit Magdeburg als Vorreiter. Das Potential dieses Ultrahochfeldgerätes (UHF) kann derzeit noch nicht voll ausgeschöpft werden, da die Hochfrequenz-Sende- und -Empfangstechnik optimiert werden muss. Hierzu werden spezielle Spulenkonfigurationen wie etwa Phase-Array-Spulen benötigt, welche derzeit nur für den Kopfbereich und von nur einer Firma kommerziell angeboten werden. Die Etablierung von HF-Kompetenz und die Entwicklung optimaler Spulen ist das Ziel des Antrages. Die erworbenen Kenntnisse und technischen Fähigkeiten sollen sekundär in Kooperationen mit der Wirtschaft und anderen Instituten weiterentwickelt und vermarktet werden. Das Projekt fügt sich harmonisch in den Schwerpunkt Biophysik und weiche Materie der FNW ein und kann als fakultätsübergreifender Kristallisationspunkt für die Initiativen im Bereich Medizintechnik gesehen werden.

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The major goals of this project are to develop new technology to overcome the limitations of ultra high field imaging in humans (higher than 7 Tesla). The project consortium consists of University Freiburg, Siemens Medical Systems, and Bruker Biospin. The University Magdeburg is sub-contractor to the University Freiburg and Siemens Medical Systems and involved in the development of methods for real-time scanner control and parallel transmission.

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Preisgeld für den Preis für Angewandte Forschung in Sachsen-Anhalt 2007, zur Förderung von Wissenschaft und Forschung.

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Menschliche visuelle Mustererkennung unterliegt einer erheblichen Plastizität: Wenn Probanden über längere Zeit trainieren, einfache Reizmuster zu unterscheiden, dann können sie die Präzision ihrer Antworten erheblich verbessern, solange Trainings- und Testbedingungen sehr ähnlich sind. Die genauen Mechanismen dieser hochselektiven Verbesserung visueller Mustererkennung sind bis heute nicht geklärt.

In diesem Projket wird untersucht, wie der Aufbau perzeptueller Kompetenzen im visuellen System durch sog. Fehlersignale unterstützt wird. Fehlersignale resultieren aus Interaktionen der Basalganglien und des präfrontalen Kortex und indizieren Differenzen zwischen erwarten und tatsächlichen Ereignissen. Diese Differenzen werden als Belohnung / Bestrafung oder, abstrakter, als Erfolg / Misserfolg kodiert und sind Bestandteil des Systems des Verstärkungslernens, das diese Feedback-Inforation verwendet, um Verhalten in Bezug auf das gewählte Ziel zu optimieren. Die hier geplanten Studien haben das Ziel, neutrale Mechanismen von perzeptuellem Lernen durch Fehlersignale zu identifizieren. Dabei kommen neue MR Verfahren (Anwendung von statistischer Mustererkennung auf hochauflösende 3T und 7T fMRT-Daten) und eine Kombination multimodaler räumlich-zeitlicher Parameter zum Einsatz.

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Motivation für die Durchführung díeses Treffens von Wissenschaftlern auch China und Deutschland von Forschungsstätten mit Hochfeld-Magnetresonanztomographie (MRT) ist die Etablierung von Hochfeld (7T) Tier-MRT und die Errichtung des ersten 7T-Human-MRT in China. Zudem befindet sich in Deutschland die größte Forschungsgemeinschaft im Bereich der Hochfeld-MRT außerhalb der USA und in Magdeburg wurde 2005 der erste 7T-Human-MRT in Europa in Betrieb genommen.

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The use of single-shot echo-planar imaging (EPI) has grown dramatically over recent years. A number of advanced brain imaging applications in functional neuroimaging, e.g. functional MRI (fMRI) and diffusion tensor imaging (DTI), use EPI as the imaging module. EPI, however, is susceptible to a number of imaging artefacts and geometric image distortions due to inhomogeneities of the main magnetic field within the sample. These inhomogeneities induced by magnetic susceptibility differences in the sample or by main field inhomogeneities are often regarded as inherently constant in time. Especially for long time-series acquisitions with continuous and repetitive scans, system instabilities, ferro-shim heating or subject s motion and respiration can introduce time dependant changes in the field homogeneity. These result in time variant changes in image distortions leading to degradation and to artefacts in time-series analyses. These effects become increasingly important at high field strengths of 3 Tesla and above, and can become a significant obstacle for EPI applications at 7T. In this project we propose an approach to dynamically measure, characterise and compensate for geometric image distortions in EPI. The project covers various EPI applications ranging from functional MRI to diffusion tensor imaging. The methods, which are to be developed, will be evaluated at various field strengths ranging from 1.5T to 7T. They will significantly improve stability and imaging properties of EPI to allow more sensitive experimental results and higher positional accuracy.

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Neue Methoden zur Untersuchung der neuronalen Aktivierung mittels Magnetresonanztomographie werden in idesem von der Hertie-Stiftung geförderten Projekt entwickelt und untersucht. Das gängige Messverfahren beruht auf dem BOLD Effekt, welcher relativ langsam (1s) einen indirekten Effekt der Gehirnaktivität misst. Neue Verfahren sollen eine direktere und schnellere Messung erlauben.

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31P-Spektroskopie ist von höchstem Interesse, da viele entscheidende Metaboliten des Zellstoffwechsels MR-sichtbare Moleküle sind, welche Phosphor enthalten. Pathologische Veränderung des Zellstoffwechsels, wie etwa durch ischämische Ereignisse hervorgerufen, können mittels 31P-Spektroskopie detektiert, beurteilt und in ihrem Verlauf oder während Therapie verfolgt werden. Hierzu gehören unter anderem Pathologien, die durch Gefäßerkrankungen hervorgerufen werden, wie etwa Schlaganfälle des Gehirns, Herzinfarkte oder aufgrund peripherer Gefäßerkrankungen minderdurchblutete Muskelgruppen. Die MR-spektroskopische Messung der 31P-Metaboliten ist jedoch aufgrund ihrer geringen Konzentration und Sensitivität im Vergleich zur Protonenbildgebung sehr zeitaufwendig. Durch die Kombination von hohen statischen Magnetfeldern mit effizienten und schnellen Verfahren zur Signalgenerierung und Bildaufnahme aus der 1H-Bildgebung können spektroskopische 31P-Aufnahmen in für die klinische Anwendung akzeptablen Zeiten durchgeführt werden. Hierzu soll in diesem Projekt das neu entwickelte und vorgestellte Verfahren des 31P-SSFP CSI bis zur klinischen Anwendbarkeit weiterentwickelt und an Patientengruppen mit verschiedenen Pathologien eingesetzt werden. Neben dieser Entwicklung und Erprobung der statischen Bildgebung soll auch untersucht werden, inwieweit die Methode sich zur direkten Visualisierung der lokalen metabolischen Transferrate von Phosphokreatin mittels Magnetization Transfer Imaging einsetzen lässt.

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