Traditional Posters: Miscellaneous
Yüklə 355,76 Kb.
|
| Sonal Josan1,2, Yi-Fen Yen3, Ralph Hurd3, Adolf Pfefferbaum4, Daniel Spielman2, Dirk Mayer, 12
1SRI International, Menlo Park, CA, United States; 2Radiology, Stanford University, Stanford, CA, United States; 3Applied Sciences Laboratory, GE Healthcare, Menlo Park, CA, United States; 4Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, United States Undersampled spiral CSI (spCSI) with free induction decay (FID) acquisition allows real-time metabolic imaging of hyperpolarized 13C. Phase correction of the FID acquisition can be difficult, especially with contributions from aliased out-of-phase peaks. This work extends the spCSI sequence to incorporate a double spin-echo obtaining high quality spectra in magnitude mode. It also provides an added benefit of attenuating signal from flowing spins. 1018. In Vivo Detection of Radiation-Induced Metabolic Response in Rat Kidneys by 13C Hyperpolarized MRSI Lasitha Senadheera1, Dirk Mayer2,3, Moses Darpolor2, Yi-Fen Yen4, Lei Xing1, Daniel Spielman2 1Radiation Oncology, Stanford University, Stanford, CA, United States; 2Radiology, Stanford University, Stanford, CA, United States; 3Neuroscience Program, SRI International, Menlo Park, CA, United States; 4Global Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States Radiation dose to the tumors is often limited by the irradiation of adjacent organs at risk, such as kidneys. Unlike structural change, metabolic response may reflect early signs of radiation damage in tissues, offering opportunity to better design radiotherapy. Following hyperpolarized [1-13C]pyruvate injection, 13C MRSI was employed to detect radiation-induced metabolic response in rat kidneys at various radiation doses and postirradiation times. No trend in Lactate/pyruvate ratios was observed between irradiated and normal kidneys of the same animal. Metabolic response of irradiated kidneys might not be strong enough to become visible in 13C MRSI, within our experimental errors and conditions. 1019. Dynamic and High-Resolution Metabolic Imaging of the Rat Brain In Vivo Using Hyperpolarized [1-13C]-Pyruvate Dirk Mayer1,2, Yi-Fen Yen3, Atsushi Takahashi3, Sonal Josan1,2, James Tropp3, Adolf Pfefferbaum1,4, Ralph E. Hurd3, Daniel M. Spielman2 1Neuroscience Program, SRI International, Menlo Park, CA, United States; 2Radiology, Stanford University, Stanford, CA, United States; 3GE Healthcare, Menlo Park, CA; 4Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, United States Time-resolved spiral chemical shift imaging was applied to investigate the uptake dynamics in the anesthetized rat brain after injection of hyperpolarized [1-13C]-pyruvate. Additionally, metabolic imaging at high spatial resolution was performed to better characterize the spatial origin of the metabolite signals. Higher lactate (Lac) and bicarbonate (Bic) signals were found in cortical regions of the brain. This could be due to higher flux of Pyr through the blood-brain barrier, faster substrate-to-product conversion, or both. Metabolite time courses from a region-of-interest in the cortex suggest slower production of Bic compared to Lac. 1020. Simultaneous Proton and Hyperpolarized Carbon Imaging Eric Peterson1, Kang Wang2, Krishna Kurpad3, Matthew Erickson2, Ian Rowland3, Sean Fain2,3 1Biomedical Engineering, University of Wisconsin - Madison, Madison, WI, United States; 2Medical Physics, University of Wisconsin - Madison, Madison, WI, United States; 3Radiology, University of Wisconsin - Madison, Madison, WI, United States Current hyperpolarized carbon protocols call for all of the scans to be performed in series, including the proton localizer and carbon metabolic image. The localizer image is typically acquired at a higher resolution than the carbon image, and eventually serves as an anatomical reference for the later carbon acquisition. By performing a simultaneous proton and carbon acquisition, several potential applications are possible such as continuous localization, motion tracking and compensation, or targeted excitation. 1021. [1-13C]lactate Signal Derived from Hyperpolarized [1-13C]pyruvate Originates from the Brain, Not from the Blood. Isabelle Iltis1, Dinesh Kumar Deelchand1, Malgorzata Marjanska1, Gregor Adriany1, Manda Vollmers1, Kamil Ugurbil1, Pierre-Gilles Henry1 1Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, United States Recently, we have shown detection of [1-13C]lactate in the normal brain in vivo after injection of hyperpolarized [1-13C]pyruvate. However, the spatial origin of the detected [1-13C]lactate signal has been a matter of debate. In the present work, a coil specifically designed to detect 13C resonances in the carotid of anesthetized, living rats was used to detect signals from the blood. We show that no lactate signal is detected in the carotid after injection of hyperpolarized [1-13C]pyruvate, hereby demonstrating that the lactate signal observed in the brain originates from tissue metabolism. 1022. Multimodal Non-Invasive Imaging of Tumor Hypoxia and Metabolism Using EPR Oxygen Imaging and Hyperpolarized 13C-MRI Shingo Matsumoto1, Doug Morris2, Martin Lizak2, Jeeva P. Munasinghe2, Keita Saito1, Jan Henrik Ardenkjaer-Larsen3, Sankaran Subramanian1, Nallathamby Devasahayam1, Kevin Camphausen1, Alan Koretsky2, James B. Mitchell1, Murali C. Krishna1 1National Cancer Institute, Bethesda, MD, United States; 2National Institute of Neurological Disorder and Stroke, Bethesda, MD, United States; 3GE Healthcare, Amersham, United Kingdom Many tumor types can undergo aerobic glycolysis, where tumors can abnormally obtain as much as 50% of their energy (ATP) by metabolizing sugar glucose directly to lactate even in the presence of oxygen. Likewise, approximately one half of tumors exhibit marked hypoxia. Collectively, these traits can contribute to resistance to cancer treatments. Non-invasive assessment of altered tumor metabolism and tissue hypoxia might be useful for both diagnostic and treatment strategies. In this study EPR oxygen imaging and hyperpolarized MRI of 13C-labeled pyruvic acid, are coupled to provide a measure of tumor hypoxia and energy metabolism. 1023. Metabolism of Hyperpolarized 1-13C-Lactate in Living Breast Cancer Cell Cultures Yüklə 355,76 Kb. Dostları ilə paylaş:
|