Traditional Posters: Miscellaneous

Non-Proton MRI

Hall B Tuesday 13:30-15:30

980. Initial Experience with 31P Imaging of Human Brain Using a Multi-Resonance, Spectral-Selective Sequence at 9.4Tesla

Aiming Lu¹, Ian C. Atkinson¹, Xiaohong Joe Zhou^1,2, Keith R. Thulborn<sup>1

1</sup>Center for MR Research, University of Illinois at Chicago, Chicago, IL, United States; ²Departments of Neurosurgery, Radiology, and Bioengineering, University of Illinois at Chicago, Chicago, IL, United States

Phosphocreatine (PCr) concentration can provide vital bioenergetic information in brain. Due to their low detection sensitivity, 31P MR signals are often detected with MRS or CSI approaches, which are either time consuming or spatial resolution limited. In this work, we report initial 31P imaging results using a spectral selective twisted projection imaging (TPI) sequence to achieve high data acquisition efficiency on a 9.4T human scanner. PCr and γ-ATP images were simultaneously obtained with whole brain coverage and reasonable SNR, temporal and spatial resolution. The ratio of the two resonances images can potentially allow detection of variation in PCr concentration.

981. In Vivo Chlorine-35, Sodium-23 and Proton Magnetic Resonance Imaging of the Rat Brain

Stefan Kirsch¹, Mark Augath², David Seiffge³, Lothar Schilling³, Lothar Rudi Schad<sup>1

1</sup>Computer Assisted Clinical Medicine, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany; ²Department of Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, Tuebingen, Germany; ³Division of Neurosurgical Research, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany

In this study we demonstrate the feasibility of combined chlorine-35, sodium-23 and proton magnetic resonance imaging (MRI) at 9.4 Tesla and, to the best of our knowledge, present the first in vivo chlorine-35 images obtained by means of MRI. With the experimental setup all measurements could be done in one session without changing the setup or moving the subject. Multinuclear MR images were acquired from a healthy rat and from a rat displaying a focal cerebral infarction. Combined in vivo chlorine-35, sodium-23 and proton MRI may provide a new approach to study diseases which involve changes in the concentration of chloride or sodium ions.

982. Hadamard-Type Pulse-Phase Encoding for Imaging of Multi-Resonant Fluorine-19 Nanoparticles in Targeted Molecular MRI

Jochen Keupp¹, Samuel A. Wickline², Gregory M. Lanza², Shelton D. Caruthers<sup>2

1</sup>Philips Research Europe, Hamburg, Germany; ²C-TRAIN, Washington University, St. Louis, MO, United States

¹⁹F-MRI allows the direct quantification of nanoparticles (NP) or fluorinated drugs in molecular imaging. Previously, α _ν β ₃-integrin targeted NP have been shown to detect and quantify angiogenesis in tumor models. Towards human translation, clinically-relevant NP-substrates like perfluoro-octyl-bromide (PFOB) should be applied, but rich spectra and large chemical shifts (CS) add significant complexity. Many methods have been developed to manage CS-artifacts, but tradeoffs like long encoding time or a need for complex corrections remain. Herein, Hadamard-type pulse phase encoding is introduced in the CS domain as a robust and efficient method to detect multi-resonant ¹⁹F labels. Feasibility is demonstrated in vitro and in vivo for angiogenesis-targeted PFOB-NP in Vx2 tumor bearing rabbits.

983. Sodium Boost SPRITE Imaging of the Human Brain