Traditional Posters: Body Imaging

Stefan Weick¹, Philipp Ehses², Martin Blaimer², F. A. Breuer², P. M. Jakob<sup>1,2

1</sup>Department of Experimental Physics 5, University of Wuerzburg, Wuerzburg, Bavaria, Germany; ²Research Center for Magnetic Resonance Bavaria (MRB)

In this work, 3D Flash examinations of the human lung were performed during free respiration using the DC signal for self-gating. Short echo times (TE) are required to provide sufficiently SNR because of the short T2* of the lung tissue. It is shown that the DC signal can be acquired after the actual imaging module still providing enough quality for respiratory gating and simultaneously providing very short echo times. The maxima and minima of the DC signal were used to define threshold values for data rejection and high resolution images were reconstructed retrospectively.

2526. Dynamic MR Perfusion Imaging Vs. Time-Resolved MR Angiography Vs. MDCT: Disease Extent Assessment and Outcome Prediction for Patients with Acute Pulmonary Thromboembolism

Keiko Matsumoto¹, Yoshiharu Ohno¹, Hisanobu Koyama¹, Yumiko Onishi¹, Daisuke Takenaka¹, Munenobu Nogami¹, Nobukazu Aoyama², Hideaki Kawamitsu², Tsutomu Araki³, Kazuro Sugimura<sup>1

1</sup>Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan; ²Division of Radiology, Kobe University Hospital, Kobe, Japan; ³Department of Radiology, University of Yamanashi, Japan

MDCT has become the first imaging examination in suspected APTE patients. As well as technical advances of CT, technical advances of magnetic resonance (MR) imaging make it possible to obtain time-resolved MR angiography or perfusion MR imaging (perfusion MRI) in APTE patients. We hypothesized that quantitatively assessed pulmonary perfusion parameters from contrast-enhanced perfusion MRI have potential for disease extent assessment and have predictive capability of patient outcome in APTE patients. The aim of our study was therefore to directly compare the capability for disease severity assessment and patient outcome prediction of MDCT and MR techniques in APTE patients.

2527. Exploration of Gas Flow During High Frequency Oscillated Ventilation by ¹⁹F-Gas-MRI

Janet Friedrich¹, Julien Rivoire¹, Alexander Wiegbert Scholz², Maxim Terekhov¹, Rainer Köbrich², Lars Krenkel³, Claus Wagner³, Laura Maria Schreiber<sup>1

1</sup>Section of Medical Physics, Department of Diagnostic and Interventional Radiology, Johannes Gutenberg University Medical Center, Mainz, Germany; ²Department of Anesthesiology, Johannes Gutenberg University Medical Center, Mainz, Germany; ³German Aerospace Center, Göttingen, Germany

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.