@phdthesis{Offenberger2009, author = {Offenberger, Wolfgang}, title = {Hochaufgel{\"o}ste Magnetresonanz-Bildgebung der M{\"a}useaorta zur Bestimmung der Dynamik funktioneller Parameter durch Laufrad-Training bei ApoE-Knock-Out-M{\"a}usen}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-35146}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2009}, abstract = {Einf{\"u}hrung: Atherosklerose ist eine f{\"u}hrende Ursache von Morbidit{\"a}t und Mortalit{\"a}t weltweit. Die ApoE-Knock-Out-Maus (ApoE-/-) ist das wichtigste Tiermodell f{\"u}r das Studium der Atherosklerose und von Interventionen auf diese Erkrankung. Mittels hochaufgel{\"o}ster Magnet-Resonanz-Bildgebung ist es m{\"o}glich, eine nicht-invasive in-vivo Gef{\"a}ß-Charakterisierung bei M{\"a}usen durchzuf{\"u}hren. In dieser Arbeit wurden die Auswirkungen von Sport auf die Gef{\"a}ßfunktion der Aorta ascendens und abdominalis bei ApoE-/--M{\"a}usen mittels hochaufgel{\"o}ster MR-Cine-FLASH-Bildgebung untersucht. Methodik und Ergebnisse: 18 ApoE-/--M{\"a}use mit oder ohne Lipid-reicher „Western Type Diet" (WTD) f{\"u}hrten 4-6 Wochen lang Laufrad-Training durch. Vor Laufrad-Training wurde zweimal (Validit{\"a}t) und nach Laufrad-Training einmal mittels EKG- und Atmungs-getriggerter Magnet-Resonanz-Cine-FLASH-Bildgebung an einem 7-Tesla-Scanner unter Isofluran-Inhalationsnarkose die Compliance von Aorta ascendens und abdominalis gemessen. Aufnahme-Parameter: TR/TE = 4,3/1,4 ms; Field of View (FOV) = 3,0 x 3,0 cm2; Matrixgr{\"o}ße = 256 x 256; Pixel-Gr{\"o}ße = (FOV / Matrix) = (30 mm / 256) = 0,0117 mm2; Schichtdicke = 1,0 mm, Aufl{\"o}sung von 0,0137 mm3. Die Resultate wurden verglichen mit 9 Wildtyp-M{\"a}usen vom Stamm C57BL/6J, und mittels der Auswerte-Software Interactive Data Language (IDL) prozessiert. Es zeigten sich gewisse positive Effekte hinsichtlich Compliance der Aorta ascendens durch Sport, die Ergebnisse waren f{\"u}r ApoE-/--M{\"a}use ohne WTD jedoch wesentlich konsistenter als f{\"u}r ApoE-/--M{\"a}use mit WTD, wo die Ergebnisse teilweise widerspr{\"u}chlich erscheinen. Dasselbe gilt f{\"u}r die Aorta abdominalis, die sich zudem in vielen MR-Untersuchungen nicht auswerten ließ, was zu nicht interpretierbaren Ergebnissen f{\"u}hrte. Bez{\"u}glich der Validit{\"a}t zeigte sich eine sehr hohe Intra-Observer- und Inter-Observer-{\"U}bereinstimmung der Ergebnisse, dies zeigte sich auch f{\"u}r Messungen zu zwei Zeitpunkten. Schlussfolgerung: Die Ergebnisse erscheinen insgesamt kritisch beleuchtet nicht signifikant und zeigen allenfalls Besserungs-Tendenzen f{\"u}r die Compliance der Aorta ascendens und abdominalis bei ApoE-/--M{\"a}usen durch Sport. Weitere MRT-Studien mit h{\"o}heren Feldst{\"a}rken und weiterentwickelten MR-Protokollen sind notwendig, um die Aussage dieser Doktorarbeit, dass Atherosklerose bei ApoE-/--M{\"a}usen durch Sport teilweise reversibel ist, zu best{\"a}tigen.}, subject = {Magnetresonanztomographie}, language = {de} } @article{NordbeckBoenhofHilleretal.2013, author = {Nordbeck, Peter and B{\"o}nhof, Leoni and Hiller, Karl-Heinz and Voll, Sabine and Arias-Loza, Paula and Seidlmaier, Lea and Williams, Tatjana and Ye, Yu-Xiang and Gensler, Daniel and Pelzer, Theo and Ertl, Georg and Jakob, Peter M. and Bauer, Wolfgang R. and Ritter, Oliver}, title = {Impact of Thoracic Surgery on Cardiac Morphology and Function in Small Animal Models of Heart Disease: A Cardiac MRI Study in Rats}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {8}, doi = {10.1371/journal.pone.0068275}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130064}, pages = {e68275}, year = {2013}, abstract = {Background Surgical procedures in small animal models of heart disease might evoke alterations in cardiac morphology and function. The aim of this study was to reveal and quantify such potential artificial early or long term effects in vivo, which might account for a significant bias in basic cardiovascular research, and, therefore, could potentially question the meaning of respective studies. Methods Female Wistar rats (n = 6 per group) were matched for weight and assorted for sham left coronary artery ligation or control. Cardiac morphology and function was then investigated in vivo by cine magnetic resonance imaging at 7 Tesla 1 and 8 weeks after the surgical procedure. The time course of metabolic and inflammatory blood parameters was determined in addition. Results Compared to healthy controls, rats after sham surgery showed a lower body weight both 1 week (267.5±10.6 vs. 317.0±11.3 g, n<0.05) and 8 weeks (317.0±21.1 vs. 358.7±22.4 g, n<0.05) after the intervention. Left and right ventricular morphology and function were not different in absolute measures in both groups 1 week after surgery. However, there was a confined difference in several cardiac parameters normalized to the body weight (bw), such as myocardial mass (2.19±0.30/0.83±0.13 vs. 1.85±0.22/0.70±0.07 mg left/right per g bw, p<0.05), or enddiastolic ventricular volume (1.31±0.36/1.21±0.31 vs. 1.14±0.20/1.07±0.17 µl left/right per g bw, p<0.05). Vice versa, after 8 weeks, cardiac masses, volumes, and output showed a trend for lower values in sham operated rats compared to controls in absolute measures (782.2±57.2/260.2±33.2 vs. 805.9±84.8/310.4±48.5 mg, p<0.05 for left/right ventricular mass), but not normalized to body weight. Matching these findings, blood testing revealed only minor inflammatory but prolonged metabolic changes after surgery not related to cardiac disease. Conclusion Cardio-thoracic surgical procedures in experimental myocardial infarction cause distinct alterations upon the global integrity of the organism, which in the long term also induce circumscribed repercussions on cardiac morphology and function. This impact has to be considered when analyzing data from respective animal studies and transferring these findings to conditions in patients.}, language = {en} } @article{AndelovicWinterJakobetal.2021, author = {Andelovic, Kristina and Winter, Patrick and Jakob, Peter Michael and Bauer, Wolfgang Rudolf and Herold, Volker and Zernecke, Alma}, title = {Evaluation of plaque characteristics and inflammation using magnetic resonance imaging}, series = {Biomedicines}, volume = {9}, journal = {Biomedicines}, number = {2}, issn = {2227-9059}, doi = {10.3390/biomedicines9020185}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-228839}, year = {2021}, abstract = {Atherosclerosis is an inflammatory disease of large and medium-sized arteries, characterized by the growth of atherosclerotic lesions (plaques). These plaques often develop at inner curvatures of arteries, branchpoints, and bifurcations, where the endothelial wall shear stress is low and oscillatory. In conjunction with other processes such as lipid deposition, biomechanical factors lead to local vascular inflammation and plaque growth. There is also evidence that low and oscillatory shear stress contribute to arterial remodeling, entailing a loss in arterial elasticity and, therefore, an increased pulse-wave velocity. Although altered shear stress profiles, elasticity and inflammation are closely intertwined and critical for plaque growth, preclinical and clinical investigations for atherosclerosis mostly focus on the investigation of one of these parameters only due to the experimental limitations. However, cardiovascular magnetic resonance imaging (MRI) has been demonstrated to be a potent tool which can be used to provide insights into a large range of biological parameters in one experimental session. It enables the evaluation of the dynamic process of atherosclerotic lesion formation without the need for harmful radiation. Flow-sensitive MRI provides the assessment of hemodynamic parameters such as wall shear stress and pulse wave velocity which may replace invasive and radiation-based techniques for imaging of the vascular function and the characterization of early plaque development. In combination with inflammation imaging, the analyses and correlations of these parameters could not only significantly advance basic preclinical investigations of atherosclerotic lesion formation and progression, but also the diagnostic clinical evaluation for early identification of high-risk plaques, which are prone to rupture. In this review, we summarize the key applications of magnetic resonance imaging for the evaluation of plaque characteristics through flow sensitive and morphological measurements. The simultaneous measurements of functional and structural parameters will further preclinical research on atherosclerosis and has the potential to fundamentally improve the detection of inflammation and vulnerable plaques in patients.}, language = {en} }