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The MRI Sepsis Score: An Innovative Tool for the Evaluation of Septic Peritonitis in Mice Using 7-Tesla Small Animal MRI

The MRI Sepsis Score: An Innovative Tool for the Evaluation of Septic Peritonitis in Mice Using 7-Tesla Small Animal MRI

The aim of this study was to evaluate the impact of small animal MRI technology for moni- toring inflammatory response in the abdomen. To the best of our knowledge, there are no published data showing the course of a septic peritonitis using MRI. This investigation could show the progression of peritonitis for the first time using the murine CASP method. Two different stent diameters were applied based upon that the well-known survival kinetics for the 18- and 16-G CASP model [7] and early morphologic changes were subsequently visu- alized by MRI. To establish MRI as a useful tool for monitoring abdominal sepsis, typical clinical signs of peritonitis were detected in the well-established CASP model. The overall aim of the study was to establish a reliable score, which could describe the course of septic peri- tonitis over time. The repetitive visualization of the status quo during the course of abdominal sepsis by MRI could become a useful tool in the diagnosis and treatment of sepsis.
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9.4 T small animal MRI using clinical components for direct translational studies

9.4 T small animal MRI using clinical components for direct translational studies

strategies and differences in commercial implementa- tions of multi-echo sequences. While there are currently only a few dedicated vendors for preclinical MRI systems, new companies are emerging, hoping to capitalize on the potential market. However, due to cost and complexity, advanced animal imaging sequences may not be readily available on all systems and will differ in their implemen- tation. Shrinking the gap between preclinical and clinical studies, while changing experimental parameters as little as possible, makes transposition of data easier. Thus the development of a dedicated small animal MRI machine using clinical software presents a major step in bridging this gap for truly translational research.
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9.4 T small animal MRI using clinical components for direct translational studies

9.4 T small animal MRI using clinical components for direct translational studies

imaging, accounting for about 23% of all examinations [ 7 ]. While small rodent imaging can be carried out on human MRI scanners, dedicated small animal systems display performance benefits such as higher temporal and spatial resolution [ 8 ]. However, these dedicated sys- tems usually operate with vendor specific software and require the reimplementation of MR sequences to facili- tate translational imaging studies. In addition to the tedi- ous reprogramming of the MRI sequences in another programming environment, this approach is also prone to creating mismatching sequences and consequently creating experimental discrepancies, which reduce trans- lational validity. That this is in fact problematic is obvious from early reports on—e.g. compare [ 9 ] for a discussion on errors in T 2 measurements due to different sampling strategies and differences in commercial implementa- tions of multi-echo sequences. While there are currently only a few dedicated vendors for preclinical MRI systems, new companies are emerging, hoping to capitalize on the potential market. However, due to cost and complexity, advanced animal imaging sequences may not be readily available on all systems and will differ in their implemen- tation. Shrinking the gap between preclinical and clinical studies, while changing experimental parameters as little as possible, makes transposition of data easier. Thus the development of a dedicated small animal MRI machine using clinical software presents a major step in bridging this gap for truly translational research.
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Quantitative tissue characterization by mechanical parameters in preclinical, small-animal models

Quantitative tissue characterization by mechanical parameters in preclinical, small-animal models

The system configuration is illustrated in Figure 3. Tomoelastography of the mouse brain was developed for a 7-T small animal MRI scanner (Bruker BioSpec 70/16, Ettlingen, Germany) using a 20-mm diameter 1H-RF quadrature volume coil [23]. The scanner was synchronized to a low-current transistor-transistor logic function generator (CGC Instruments, Chemnitz, Germany) based on a 10-MHz harmonic signal. The function generator was connected to the trigger output of the scanner and was controlled by the imaging sequence with trigger signals. The trigger signals select and initiate the desired mechanical vibration with the desired frequency. This strategy, called smart triggering [1], makes it possible to define and run multifrequency measurements without any user interaction during the measurements.
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Digital PET/MRI for preclinical applications

Digital PET/MRI for preclinical applications

One of the main technological challenges is to develop a scalable PET detector architecture that is capable of supplying, controlling, cooling, synchronizing, and reading out a high number of detector channels, while at the same time keeping its interference with the MRI operation low. Multiple research groups worldwide are working on solutions to enable simultaneous PET/MR imaging (Vandenberghe and Marsden, 2015). Ideas range from using optical fibers to transport the scintillation light of each detector crystal to the PET detector electronics placed far away from the MRI gantry (Shao et al., 1997) to battery-powered detector modules modulating analog laser-light signals (Olcott et al., 2013). Unfortunately, such methods are often unable to be scaled to larger systems, face MRI compatibility problems, and suffer from degraded PET performance. The approach followed in this thesis is to digitize the PET sensor signals as closely to the sensors as possible in order to maximize the PET Signal-to-Noise Ratio (SNR). The digitization thus occurs directly within the PET detector modules, which are placed inside the bore of the MRI scanner. In a second step, the sensors measure the signals directly digitally. The downside of this approach is that it has the highest risk of influencing the MRI scanner. Digital electronics are known to disturb the MRI system in several ways: the homogeneity of the static magnetic field (B 0 ) becomes
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MRI-based skeletal hand movement model

MRI-based skeletal hand movement model

It is impossible to consider all possible postures of each joint as they are infinite. Ideal, therefore, would be a very dense sampling of postures during a large number of different movements. This is not possible in MRI due to cost and time constraints. Hand postures for this work are selected so that for each joint, the extremes and some intermediate positions are covered. The selection of postures influences the resulting model in the way that multiple recordings of similar joint postures assign them a greater weight compared to postures that occur only once.

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Comprehensive Small Animal Imaging Strategies on a Clinical 3 T Dedicated Head MR-Scanner; Adapted Methods and Sequence Protocols in CNS Pathologies

Comprehensive Small Animal Imaging Strategies on a Clinical 3 T Dedicated Head MR-Scanner; Adapted Methods and Sequence Protocols in CNS Pathologies

3.5. MR imaging of a rat model of ischemic stroke. Three male Wistar rats weighing 250–300 g were considered for this study. Following anaesthesia induction, the animals were endotracheally intubated and mechanically ventilated (RS Biomed ventilator, Sinzing, Germany) with 1.5% Isoflurane in 30%:70% oxygen:nitrous oxide mixture. The femoral vein was exposed and cannulated for contrast agent injection. Transient middle cerebral artery occlusion (tMCAO) was then performed for inducing cerebral ischemia as described by Longa et al. with modifications by Spratt et al.[26,27]. One hour following tMCAO, animals were anaesthetized as mentioned before, mounted on the animal holder of the scanner and the body temperature was kept maintained. After acquiring localizer images, DW-EPI acquisitions with trace weighted apparent diffusion co-efficient (ADC) maps were generated to confirm ischemic injury followed by T 2 -weighted turbo spin-echo (T 2 -TSE)
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Significance of MRI perivascular spaces in MS

Significance of MRI perivascular spaces in MS

Of 214 preterm infants studied at Wilhelmina Children's Hospital, Utrecht, the Netherlands, 94 (44%) had a grade 111 intraventricular hemorrhage (1VH), and 120 (56%) had. a grade IV hemo[r]

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In-office magnetic resonance imaging (MRI) equipment ownership and MRI volume among medicare patients in orthopedic practices

In-office magnetic resonance imaging (MRI) equipment ownership and MRI volume among medicare patients in orthopedic practices

Thus, the choice of using onsite or shared MRI equip- ment is a variant of the classic “make or buy” decision in organizational economics, which is mainly influenced by scope economies and transaction economies [23–29]. The make-or-buy decision has been studied extensively in the context of transaction cost economics, which posits that the boundaries of organizations are in large part a function of the nature of the business transacted, where relatively complex transactions are more effi- ciently organized in settings that feature stronger admin- istrative controls, such as ownership [23, 27, 29]. In the market for medical care, consumer transaction costs are the costs incurred to the consumer to complete a trans- action, including the time necessary to implement in- formed choice, such as evaluating, choosing and locating a care provider, as well as the time spent directly obtain- ing the services [22]. Consumer transaction costs are ex- pected to be lower in the case of onsite MRI availability because patients may be able to economize on identify- ing, vetting, locating and traveling to a provider [30]. In addition, there are several potential convenience-related benefits associated with onsite availability, including
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Synthese von Gd(II)-Komplxen für die molekulare MRI

Synthese von Gd(II)-Komplxen für die molekulare MRI

Nach Ablauf dieser Zeit werden alle flüchtigen Bestandteile im Ölpumpenvakuum entfernt und zu dem Rückstand CHCl 3 gegeben.. Die Suspension wird mit 3×5ml Wasser ausgeschüttelt.[r]

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Gestalt und Funktion von Animal Design : Versuch einer semiotischen Analyse

Gestalt und Funktion von Animal Design : Versuch einer semiotischen Analyse

22 Für die Entstehung des Metaphern Design grundlegend war die zunehmende Miniaturisierung insbesondere technischer Geräte, durch die es zu „indirekten Schrumpfprozessen“ kam. 86 Dadurch reduzierte sich die Designaufgabe auf die Gestaltung der Benutzeroberfläche, wodurch der gestalterische Schwerpunkt von der Körper-Semantik auf die Produkt-Grafik überging. 87 Mit dem Schwinden der Mechanik in den Produkten und dem zunehmenden Anteil an Mikroelektronik verlor der durch Sullivan geprägte traditionelle Design-Grundsatz „form follows function“ (s. u.) seine Grundlage. Diesem zufolge wurde ein Produkt von „innen nach außen“ entwickelt, bestimmten die technisch-praktischen Funktionen und nicht die Oberfläche den Ausdruck. Beim „Metaphern Design“ werden Produkte im Gegensatz dazu „von außen her“ entwickelt. 88 Da sich diese Produkte nicht mehr selbst zu erklären vermögen, sind sie auf ein entsprechendes Gehäusedesign angewiesen, was notwendigerweise zu Stilblüten führt. 89 Hierzu zählen z. B. Stichsägen in Wespen- oder Termitendesign oder „Wellness“-Massagegeräte, die an Haifische erinnern. Uri Friedländer und Winfried Scheuer versuchen bewusst, diese Entwurfstendenzen auf technische Geräte anzuwenden. Beide sehen in technischen Produkten nicht nur praktische Apparaturen, sondern solche mit symbolischen Funktionen und vertreten die Auffassung, dass die rational-analytische Orientierung des Designs durch emotional-sinnliche Werte ersetzt werden müsse. 90 In diesem Sinne ergeben sich deutliche Parallelen zu Produkten im Animal Design. Unter dem Aspekt der Produktsprache betrachtet geht Animal Design jedoch über die gestalterischen Grenzen der technischen Produkte hinaus, daher kann es gegenüber dem Metaphern Design als übergeordnete Kategorie betrachtet werden.
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Animal spirits: Die verhaltensökonomischen Grundlagen der Keynesschen Theorie

Animal spirits: Die verhaltensökonomischen Grundlagen der Keynesschen Theorie

In der Keynesschen Theorie handeln die ökonomischen Akteure (Unternehmer, Arbeitnehmer, Konsumenten, Spekulanten) unter unvollkommener Information, begrenzten Informationssammlungs- und Verarbeitungskapazitäten, in einer Geldwirtschaft ohne Auktionator - dem Ersatz für perfekte Informationen im walrasianischen Modell-, die Vorsichtssparen, Spekulation, Investitionen und Handel zu nicht Gleichgewichtspreisen ermöglicht, in einer Ökonomie, in der Entscheidungen auf Erwartungen beruhen, die nicht auf kalter Kalkulation sondern auch von Emotionen, Intuition, Konventionen, Routinen, Heuristiken und Animal Spirits beeinflusst werden. Im Gegensatz zum (unterstellten) stabilen Marktgleichgewicht der Neoklassik, das nur durch externe Schocks gestört werden kann, lässt die Keynessche Theorie eine endogene Instabilität der Märkte zu.
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Hoffnung jenseits der Illusion: Global Animal Law

Hoffnung jenseits der Illusion: Global Animal Law

metaphor of the "universal cultural lens", a lens through which all cultures see animal issues as a common concern and accept overarching moral, ethical, empirical and other principles that might apply to the human-animal-relationship. This method is supported by studies in bioethics, psychology and sociology. Then, existing institutions, groups and events should be assessed by a hypothetical independent, responsible and caring person. As a second step, the value judgments need to be implemented in law. By doing so, common principles are applied to specific situations, which results in e.g. a prohibition of skinning animals alive.
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Nomadic animal movements and their conservation challenges

Nomadic animal movements and their conservation challenges

herbivores and have been considered as central places where animals must return to periodically resulting in constrained movements of water-dependent species (Bleich et al., 2010; Rozen- Rechels et al., 2015). For example, feral horses in Sable Island National Park in Canada occurred close to water sources during summer time (Rozen-Rechels et al., 2015) and the distribution of waterbuck in Kruger National Park in South Africa was constrained by surface water availability (Redfern et al., 2003). Numerous studies have shown that animals access forage further away from water sources until they have to return to water resulting in a commuting pattern between forage and water resources. A recent study on effects of spatial memory on movement decisions has demonstrated that wide-ranging elephants in African savanna showed highly directional rapid movements to the closest water sources, indicating detailed spatial memory allowing them to minimize travel distance to water resources (Polansky et al., 2015). In the xeric Gobi desert, a previous study suggested return movements of khulan to sparsely distributed small springs and large oases, whose locations are spatially static, but availability of water at these locations is temporally unpredictable (Nandintsetseg et al., 2016). While our findings generally support the notion that an environmental gradient from mesic to xeric conditions modulates return
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Animal Hoarding - rechtliche Aspekte / eingereicht von Julia Kljuna

Animal Hoarding - rechtliche Aspekte / eingereicht von Julia Kljuna

1999 veröffentlicht Patronek die erste Studie über Animal Hoarding in den USA. Dabei wurde der Begriff Animal Hoarding erstmals definiert und es wurde aufgezeigt, dass es sich hierbei um ein ernsthaftes Problem handelt, das jeden Staat der USA betrifft. Laut Patronek wird das Sammeln von Tieren dann problematisch, wenn den Hoardern die Anzahl der Tiere über den Kopf wächst und sie die Tiere nicht mehr ordnungsgemäß versorgen können. Es ist nicht unüblich, dass die Hoarder in ihren Wohnungen, Häusern, Autos oder Wohnwägen dutzende bis zu hunderte Tiere – lebend und tot – eingesperrt haben. Euthanasie ist aufgrund des schlechten Gesundheitszustandes, den ansteckenden Krankheiten und der Vielzahl von Tieren, leider oftmals nur die einzige Möglichkeit, die Tiere von ihrem Leid zu befreien, die aus einem solchen Haushalt gerettet wurden. Der englische Begriff Animal Hoarding („Tierhorten“ oder „Tiersammel-Sucht) bezeichnet somit das pathologische Sammeln und Horten von Tieren. Nach Patroneks Definition ist ein Animal Hoarder somit eine Person, die eine Vielzahl von Tieren in seinen Haushalt hält und dabei nicht mehr imstande ist, die Mindestanforderungen an Nahrung, Hygiene und tierärztlicher Versorgung zu gewährleisten. Die Person handelt nicht, obwohl sich der Zustand der Tiere und seiner Umgebung verschlechtert. Durch die Vernachlässigung kommt es häufig zu Erkrankungen, zum Verhungern oder sogar zum Tod der Tiere, was gleichermaßen oft zu negativen Auswirkungen auf das Wohlbefinden und die Gesundheit der Hoarder sowie auch auf die von anderen Haushaltsmitgliedern führt. 41
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Accelerated Quantitative Mapping of Relaxation Times in MRI

Accelerated Quantitative Mapping of Relaxation Times in MRI

The domain of quantitative mapping in MRI is newly formed and needs to be explored in clinical studies: For example, studies to understand the pathophysiology of neurode- generative disease, by investigating brain iron content [30] using quantitative T2*-maps, or the study to understand white matter (WM) signal abnormalities observed in T2- weighted MRI scans in pre-term infants, which might be caused by developmental stage or diffuse micro-structural white matter abnormalities [19]. This study uses quantitative T2-mapping to be independent from field-inhomogeneities and susceptibility. Moreover, studies to build up knowledge of normative ranges of relaxometry-values are important. For example a study to investigate T1 and T2 relaxation in neonatal brain, the rela- tionship between these rates and their potential use for gray matter (GM) and WM discrimination [43]. However, these studies are rare due to the long acquisition times, usually associated with these measurements. Therefore, decreasing the acquisition time using model-based iterative reconstruction will encourage clinicians to further investigate quantitative mapping.
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Respiratory and cardiac self-gated radial MRI

Respiratory and cardiac self-gated radial MRI

For each reconstructed image sequence, the image sharp- ness was calculated. For cardiac images, a profile was placed over the septal myocardial wall in the end- diastole frame as shown in Figure 3. For TMJ images the profile was placed over the condyle edge, in the center- frame between the open and the closed position. Edge sharpness was calculated as the mean intensity slope between the 20% and 80% signal level of the profile similar to (23). Significance of sharpness increase was assessed for TMJ using the one-sided Wilcoxon signed rank test. No significance tests were performed for cardi- ovascular magnetic resonance due to the small number of cases. A quantitative analysis of the left ventricular blood pool area was done using one short axis slice cine and standard software [Segment, Medviso, Lund, Swe- den (24)].
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Real-time cardiac MRI in the mouse model

Real-time cardiac MRI in the mouse model

Real-time imaging refers to the rapid and continuous acquisition of image datasets followed by image reconstruction and visualization. To reduce acquisition times, dedicated real-time methods for the rapid and continuous acquisition of image datasets, such as parallel imaging(Breuer et al., 2005; Griswold et al., 2002; Seiberlich et al., 2011), k-t acceleration methods(Bollache et al., 2018; Feng et al., 2013; Schnell et al., 2014), and compressed sensing (CS)(Kido et al., 2016; Lustig et al., 2007; Otazo et al., 2010), have been suggested and initially evaluated(Wech et al., 2016). As the MRI data are redundant, acceleration can be achieved by undersampling, thus reducing the amount of acquired data for a single frame of an image series. Iterative reconstruction algorithms ensure image fidelity, e.g. by adding spatial and temporal regularization. Recent progress in real-time MRI result in high quality images with high signal-to- noise ratio (SNR), adequate spatial resolution and unsurpassed temporal resolution(Frahm et al., 2019; Uecker et al., 2010; Xue et al., 2013; Zhang et al., 2010).
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Anatomical and functional lung imaging with MRI

Anatomical and functional lung imaging with MRI

Upon completion of imaging, each animal was euthanized using an overdose of pentobarbital (250 mg/kg intraperitoneally). Im- mediately after euthanasia, right and left lungs were dissected out, fixed with 4% paraformaldehyde (prepared in phosphate- buffered saline, pH 7.2) in in flation using intratracheal injection, and embedded in paraffin. Lungs were' cut parallel to the main bronchus and sliced with a thickness of 3 μm. Slides were stained using hematoxylin and eosin and digitally scanned with a Zeiss Axio Scan.Z1 (Jena, Germany) with 20× magnification. Im- ages were exported with 1:4 setting and cut into tiles of 1024 × 1024 pixels (1 pixel ≅ 0.88 μm). Tiles with less than 40% coverage of lung tissue and tiles including airways, blood vessels or arti- facts were rejected. For the remaining tiles the mean linear inter- cept (MLI) (36) was automatically determined using a proprietary application based on a commercially available machine vision software library (HALCON 12.0, MVTec Software, Munich, Germany) to evaluate the presence and severity of emphysematous changes.
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Messung der Nierenperfusion mittels DCE-MRI am narkotisierten Schwein

Messung der Nierenperfusion mittels DCE-MRI am narkotisierten Schwein

gen zunehmend die MR-Tomographie eingesetzt. Ein Beispiel hirfür ist die nichtinvasive Perfusi- onsmessung mittels MRT nach dem Prinzip des Spin-Labelings. Detre beschrieb 1992 erstmals die direkte magnetische Markierung einfließenden Blutes und deren Nachweis im Gewebe (Detre, Leigh et al. 1992). Das im Blut vorhandene Wasser wird dabei als intrinsischer Tracer verwendet. Das Verfahren hat nach bisheriger Kenntnis neben der Nichtinvasivität den Vorteil, dass die physi- kochemischen Verbindungen reversibel und ohne Auswirkung auf die Hämodynamik sind. Auswir- kungen auf den Stoffwechsel sind derzeit nicht bekannt und werden allgemein als vernachlässigbar angenommen. Es ist jedoch zu bedenken, dass obwohl magnetisch angeregte Moleküle durchaus andere physikochemische Eigenschaften aufweisen als nichtangeregte, Störungen des intrazellulä- ren Stoffwechsels nicht sicher ausgeschlossen werden können. Der häufig nach 3-Tesla-MRT- Untersuchungen beim Menschen auftretende Schwindel und Übelkeit könnte in diesem Sinne als möglicher Hinweis auf eine solche Störung z. B. der molekulären Mechanismen des Kinozilienap- parates der Bogengänge und/oder der zentralen Reizverarbeitung gedeutet werden. Die Perfusion lässt sich quantifizieren, wobei Buxton et al. die wohl umfassendste theoretische Beschreibung in ihrem „general kinetic model“ liefern (Buxton RB, Lawrence RF et al. 1998; Warmuth 2003). Ein Schwerpunkt dieser Arbeit war die Messung der Nierenperfusion in vivo bei einem narkotisier- ten Schwein im MRT vermittels DCE-MRI (Dynamisch-kontrastverstärkte Magnetresonanztomo- graphie). Gemessen wurde die Nierenperfusion am ruhenden, narkotisierten Schwein ohne Einen- gung der Nierenarterie („Ruhebedingungen“), und nach gezielter schrittweiser Reduktion des Nierenflusses. Dies wurde durch Veränderung des Innendurchmessers einer implantierten Man- schette (Nierenerteriendrossel) erreicht. Um zu überprüfen, in welchem Umfang die im MRT ge- wonnenen Messergebnisse mit den tatsächlichen lokalen Perfusionswerten übereinstimmten, wurde die Perfusion mittels einer Ultraschalldopplersonde (s. Beschreibung 3.1.6) bestimmt. Diese Me- thode ist validiert und gilt als Referenzstandard für derartige Messungen (s. u.). Somit konnte der mittlere RBF/MRT verglichen werden mit dem mittleren RBF, gemessen mit der Dopplersonde. Die Messung von intravasalem Blutfluß vermittels Dopplerflußmessung stellt momentan den „Gold- standard“ hierfür dar.
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