Dr. rer. nat.
Diagnostic Radiology and Nuclear Medicine
Lead, Metabolic Imaging Program
After completing my doctorate at the University of Bremen in Germany in 2000, I spent three years as a postdoctoral fellow at Stanford University in the Department of Radiology, followed by three years as a Research Associate. From 2007 to 2013 I held joint appointments as Senior Research Scientist at Stanford University and SRI International, and in 2013 I joined the faculty at the University of Maryland, Baltimore.
My research focuses on the development of MRI-based imaging techniques for the noninvasive investigation of metabolic processes under both normal and pathologic conditions that can be applied in preclinical and clinical settings. In particular, my research interests have centered on the use of dynamic nuclear polarization to increase the MR signal of metabolically active, 13C-labeled compounds for in vivo metabolic imaging. Specific areas of research include optimized acquisition and reconstruction techniques, kinetic modeling for quantitative analysis, and new probe development. At this time, I am exploring the application in tumor diagnosis and treatment monitoring, and in the study of cardiovascular and liver pathologies, inflammatory diseases, and brain metabolism.
I am a member of the Experimental Therapeutics Program within the University of Maryland Marlene and Stewart Greenebaum Cancer Center Program in Oncology. Experimental Therapeutics researchers collaborate with both basic and clinical research investigators, focusing on the rapid transfer of knowledge from the laboratory to the clinic. Together with my collaborators I develop imaging techniques for cancer diagnosis, treatment monitoring, and prediction of response to therapy.
- D. Mayer, Y-F. Yen, J. Tropp, A. Pfefferbaum, R.E. Hurd, D.M. Spielman "Application of Sub-Second Spiral Chemical Shift Imaging to Real-Time Multi-Slice Metabolic Imaging of the Rat In Vivo after Injection of Hyperpolarized 13C1-Pyruvate", Magn. Reson. Med., 62, 557-564, 2009.
- Y-F. Yen, P. LeRoux, D. Mayer, R. King, D.M. Spielman, J. Tropp, K. Butts-Pauly, A. Pfefferbaum, S. Vasanawala, R.E. Hurd "T2 Relaxation Times of 13C Metabolites in a Rat Hepatocellular Carcinoma Model Measured In Vivo Using 13C-MRS of Hyperpolarized [1-13C]Pyruvate", NMR in Biomed., 23, 414-423, 2010.
- D. Mayer, Y-F. Yen, Y.S. Levin, J. Tropp, A. Pfefferbaum, R.E. Hurd, D.M. Spielman "In Vivo Application of Sub-Second Spiral Chemical Shift Imaging (CSI) to Hyperpolarized 13C Metabolic Imaging: Comparison with Phase-Encoded CSI", J. Magn. Reson., 204, 340-345, 2010.
- R.E. Hurd, Y-F. Yen, J. Tropp, A. Pfefferbaum, D.M. Spielman, D. Mayer "Cerebral Dynamics and Metabolism of Hyperpolarized [1-13C] Pyruvate using Time Resolved MR Spectroscopic Imaging", J. Cereb. Blood Flow Metab., 30:1734-1741, 2010.
- M.M. Darpolor, Y-F. Yen, W. Shi, L. Xing, R.H. Clarke-Katzenberg, M.-S. Chua, D. Mayer, S. Josan, R.E. Hurd, A. Pfefferbaum, L. Senadheera, S. So, L. Hofmann, G.M. Glazer, D.M. Spielman "In Vivo Magnetic Resonance Spectroscopic Imaging of Hyperpolarized [1-13C]-Pyruvate Metabolism in Rat Hepatocellular Carcinoma", NMR in Biomed, 24:506-513, 2011.
- S. Josan, Y-F. Yen, R. Hurd, A. Pfefferbaum, D. Spielman, D. Mayer "Application of Double Spin-Echo Spiral Chemical Shift Imaging to Rapid Metabolic Mapping of Hyperpolarized 13C-Pyruvate", J. Magn. Reson., 209:332-336, 2011. PMCID:
- T. Xu, D. Mayer, M. Gu, Y-F. Yen, S. Josan, E. Johansson, J. Tropp, R.E. Hurd, D.M. Spielman "Quantitation of In-Vivo Metabolic Kinetics of Hyperpolarized Pyruvate in Rat Kidneys using Dynamic 13C Magnetic Resonance Spectroscopic Imaging", NMR in Biomed., 24:997-1005, 2011.
- S. Josan, D. Spielman, Y-F. Yen, R. Hurd, A. Pfefferbaum, and D. Mayer "Fast volumetric imaging of ethanol metabolism in rat liver with hyperpolarized [1-13C]-pyruvate", NMR in Biomed., 25:993-999, 2012.
- J.M. Park, S. Josan, T. Jang, M. Merchant, Y.-F. Yen, R. Hurd, L. Recht, D. Spielman, D. Mayer "Metabolite Kinetics in C6 Rat Glioma Model Using MRSI of Hyperpolarized [1-13C]Pyruvate", Magn. Reson. Med., 68:1886-1893, 2012.
- S. Josan, R. Hurd, K. Billingsley, L. Senadheera, J.M. Park, Y-F. Yen, A. Pfefferbaum, D. Spielman, D. Mayer "Effects of isoflurane anesthesia on hyperpolarized 13C metabolic measurements in rat brain", Magn. Reson. Med., 70:1117-1124, 2013.
- R.E. Hurd, D.M. Spielman, S. Josan, Y-F. Yen, A. Pfefferbaum, D. Mayer "Exchange-linked dissolution agents in dissolution-DNP 13C metabolic imaging", Magn. Reson. Med., 70:936-942, 2013.
- S. Josan, T. Xu, Y-F. Yen, R.E. Hurd, J. Fereira, C.-H. Chen, A. Pfefferbaum, D. Mayer, D. Spielman "In vivo measurement of aldehyde dehydrogenase-2 activity in rat liver ethanol model using dynamic MRSI of hyperpolarized [1-(13) C]pyruvate", NMR in Biomed., 26:607-612, 2013.
- J.M. Park, L. Recht, S. Josan, M. Merchant, T. Jang, Y.-F. Yen, R. Hurd, D. Spielman, D. Mayer "Metabolic Response of Glioma to Dichloroacetate Measured in vivo by Hyperpolarized 13C Magnetic Resonance Spectroscopic Imaging", Neuro-Oncology, 5:433-41, 2013.
- J.M. Park, S. Josan, T. Grafendorfer, Y.-F. Yen, R. Hurd, D. Spielman, D. Mayer "Measuring Mitochondrial Metabolism in Rat Brain in vivo using MR Spectroscopy of Hyperpolarized [2-13C]Pyruvate", NMR in Biomed., 26:1197-1203, 2013.
- S. Josan R. Hurd, J.M. Park, Y.-F. Yen, R. Watkins, A. Pfefferbaum, D. Spielman, D. Mayer "Dynamic metabolic imaging of hyperpolarized [2-13C]pyruvate using spiral CSI with alternating spectral band excitation", Magn. Reson. Med., 71:2051-2058, 2014.