TY - GEN A1 - Friedrich, Janet A1 - Rivoire, Julien A1 - Scholz, Alexander A1 - Wiegbert, A1 - Terekov, Maxim A1 - Kbrich, Rainer A1 - Krenkel, Lars A1 - Wagner, Claus A1 - Schreiber, Laura Maria T1 - Exploration of Gas Flow During High Frequency Oscillated Ventilation by 19F-Gas-MRI T2 - Proceedings of the International Society for Magnetic Resonance in Medicine N2 - To detect convective gas flow inside the large airways during high frequency oscillated ventilation (HFOV) the fluorinated contrast gas Heptafluoropropane was used for 19F-MRI. In a first study the comparison between constant flow measurements and Computational Fluid Dynamics (CFD) simulations provided a good agreement. In a following experiment oscillated flow was applied to a lung phantom consisting of ventilation bag and long pipe. The pressure wave inside the pipe was explored point-by-point and corresponding velocities were determined. With these experiments it could be shown for the first time that flow measurement during HFOV using fluorinated contrast gas is feasible. Y1 - 2010 UR - https://archive.ismrm.org/2010/2527.html VL - 18 ER - TY - CHAP A1 - Krenkel, Lars A1 - Pennecot, Julien A1 - Lenz, Christian A1 - Feldmann, Daniel A1 - Wagner, Claus ED - Füssel, Jens ED - Koch, Edmund ED - Malberg, Hagen T1 - Optimierung der Hochfrequenz-Oszillationsventilation mittels strömungsmechanischer Methoden und kontrastgasgestützter Magnetresonanztomografie - Teilprojekt: Rekonstruktion von Geometrien aus medizinischen Bilddaten und Erstellung von Modellen für experimentelle Strömungsuntersuchungen T2 - Laseranwendung in der Medizin, Erfassen und Verarbeiten kardiovaskulärer Signale, protektive Beatmungskonzepte : 3. Dresdner Medizintechnik-Symposium - mit DFG-Forschungsschwerpunkt Protektive Beatmungskonzepte, 6. bis 9. Dezember 2010, Dresden N2 - Der vorliegende Artikel skizziert die neu entwickelte Prozesskette für detailgenaue Rekonstruktion von Geometrien anhand medizinischer Bilddaten sowie die Herstellung von transparenten Modellen für experimentelle Untersuchungen mit bildgebenden Strömungsmessverfahren. Die Geometriedaten und Modelle werden für systematische Untersuchungen der komplexen Transportvorgänge in den Atemwegen bei künstlicher Beatmung mittels Hochfrequenzoszillationsventilation (HFOV) verwendet. Y1 - 2010 UR - https://elib.dlr.de/66863/ SN - 978-3-942710-02-2 SP - 107 EP - 114 PB - TUDpress CY - Dresden ER - TY - CHAP A1 - Scholz, Alexander-Wigbert K. A1 - Krenkel, Lars A1 - Terekhov, Maxim A1 - Friedrich, Janet A1 - Rivoire, Julien A1 - Köbrich, Rainer A1 - Wolf, Ursula A1 - Kalthoff, Daniel A1 - David, Matthias A1 - Wagner, Claus A1 - Schreiber, Laura Maria ED - Hirschel, Ernst Heinrich ED - Schröder, Wolfgang ED - Fujii, Kozo ED - Haase, Werner ED - Leer, Bram ED - Leschziner, Michael A. ED - Pandolfi, Maurizio ED - Periaux, Jacques ED - Rizzi, Arthur ED - Roux, Bernard ED - Shokin, Yurii I. ED - Klaas, Michael ED - Koch, Edmund ED - Schröder, Wolfgang T1 - Magnetic Resonance Imaging and Computational Fluid Dynamics of High Frequency Oscillatory Ventilation (HFOV) T2 - Fundamental Medical and Engineering Investigations on Protective Artificial Respiration N2 - In order to better understand the mechanisms of gas transport during High Frequency Oscillatory Ventilation (HFOV) Magnetic Resonance Imaging (MRI) with contrast gases and numerical flow simulations based on Computational Fluid Dynamics(CFD) methods are performed. Validation of these new techniques is conducted by comparing the results obtained with simplified models of the trachea and a first lung bifurcation as well as in a cast model of the upper central airways with results achieved from conventional fluid mechanical measurement techniques like e.g. Laser Doppler Anemometry (LDA). Further it is demonstrated that MRI of experimental HFOV is feasible and that Hyperpolarized 3He allows for imaging the gas re-distribution inside the lung. Finally, numerical results of oscillatory flow in a 3rd generation model of the lung as well as the impact of endotracheal tubes on the flow regime development in a trachea model are presented. KW - Central Airway KW - computational fluid dynamics KW - Computational Fluid Dynamics Simulation KW - Laser Doppler Anemometry KW - Magnetic Resonance Imaging Measurement Y1 - 2011 SN - 978-3-642-20325-1 U6 - https://doi.org/10.1007/978-3-642-20326-8_7 VL - 116 SP - 107 EP - 128 PB - Springer CY - Berlin, Heidelberg ER - TY - CHAP A1 - Friedrich, Janet A1 - Feldmann, Daniel A1 - Krenkel, Lars A1 - Wagner, Claus A1 - Schreiber, Laura Maria T1 - 19F Gas Flow Measurement of C3F7H During Constant Flow and High Frequency Oscillatory Ventilation T2 - Discovery, innovation & application - advancing mr for improved health : ISMRM 21st Annual Meeting & Exhibition ; SMRT 22nd Annual Meeting Salt Lake City, Utah, USA 20-26 April 2013 N2 - The aim of the current study is the development of MRI methods that enable the investigation of gas flow mechanisms during high frequency oscillatory ventilation. This work includes flow measurements during three constant flows (19.9, 30.6 and 41.4 L min-1) and the comparison to direct numerical simulations (DNS) using a second-order-acurate finite-volume method and to data measured with a volume flow meter. 19F-MRI, DNS and flow meter data are in good agreement. Flow measurements during HFOV of 4 Hz were successfully performed and velocity profiles could be recorded at different phases of the ventilation cycle. Y1 - 2013 UR - https://archive.ismrm.org/2013/1482.html VL - 21 ER -