Shalom Michaeli, PhD

My research is focused on relaxations during radiofrequency irradiation and development of non-invasive contrast methods for Magnetic Resonance (MR) imaging and spectroscopy at high magnetic fields (3T and higher). This research effort has resulted in numerous contributions that have fundamentally impacted brain and body research. Rotating frame relaxation methods based on adiabatic pulses were first developed in our laboratory at CMRR in Minnesota. We followed this development with a large body of work (utilizing theoretical modeling and experiments) investigating different relaxation pathways in vivo at different magnetic field strengths. The novel MR contrasts and protocols developed in my group were proven to provide an excellent tool for investigation of neurodegenerative processes in Parkinson’s disease as well as cancer and stroke. It has been 3 years that we applied our rotating frame relaxation methods T1? and T2? to investigate iron accumulation and neuronal loss, respectively, in substantia nigra (SN) of Parkinson’s disease patients. Recently we developed rotating frame method that comprises two relaxation pathways, T1? and T2?. This method provides greater sensitivity to molecular motion and is entitled Relaxation Along a Fictitious Field (RAFF). Utilization of fictitious fields in MRI is an important aspect of research in my group.

• "MRI Contrast from Relaxation Along a Fictitious Field (RAFF)” T. Liimatainen, D. J. Sorce, M. Garwood, S. Michaeli Magn Reson Med, 2010, 64(4): 983-94
• “Probing Slow Dynamics by Adiabatic R1? and R2? NMR Experiments” S. Mangia, N.J. Traaseth,G. Veglia, M. Garwood, S. Michaeli J. Am. Chem. Soc, 2010, 132(29): 9979-81
• “Frequency Offset Dependence of Rotating Frame Relaxation Rate Constants: relevance to MRS investigations of metabolite dynamics in vivo”
• S. Mangia, T. Liimatainen, M. Garwood, Pierre-Gilles Henry, Dinesh Deelchand, S. Michaeli NMR Biomed, in press
• “Proton Resonance Frequency Shift Coefficient of Thermo-Chemical Ablation Salt Solutions for MR Thermometry” D. Shrivastava, T. Hanson, U. Goerke, M. Shenoi, S. Michaeli, J.T. Vaughan, E.Cressman International Journal of Hyperthermia, 2010, submitted
• “T1? and T2?MRI in the evaluation of Parkinson’s disease” Nestrasil, S. Michaeli, T. Liimatainen ,C. E. Rydeen , C. M. Kotz, J. P. Nixon , T. Hanson , P. J. Tuite J Neurol, 2010, 257,964-968
• “Theoretical Simulations of Rotating Frame Relaxations during Adiabatic Pulses versus Conventional Spin-lock” S. Mangia, T. Liimatainen, D. J. Sorce, K. Ugurbil, M. Garwood, S. Michaeli Magn Reson Imaging 2009; 27:1074-1087
• “ Detection of Neuronal Loss using T1? MRI Assessment of 1H2O Spin Dynamics in the Aphakia Mouse” S. Michaeli, T. Burns, E. Kudishevich, T. Hanson, D. Sorce, M. Garwood, W. C. Low J Neurosci Meth 2009; 177:160-167
• “Quantitative assessment of water pools by T1? and T2? MRI in acute cerebral ischemia of the rat” K. T. Jokivarsi, J. P. Niskanen, S. Michaeli, H. I. Gröhn, M. Garwood, R. A. Kauppinen, O. H. Gröhn J Cerebr Blood F Met 2009; 29:206-16
• “Water spin dynamics during apoptotic cell death in glioma gene therapy probed by T1? and T2?” A. Sierra, S. Michaeli, J. P. Niskanen, P. K. Valonen, H. I. Gröhn, S. Ylä-Herttuala, M. Garwood, O. H. Gröhn Magn Reson Med, 2008; 59:1311-1319
• “Relaxation During Adiabatic Radiofrequency Pulses” D. Sorce, S. Michaeli, M. Garwood Curr Anal Chem 2007; 3:239-251
• “T2? and T1? Adiabatic Relaxations and Contrasts” S. Michaeli, D. Sorce, M. Garwood Curr Anal Chem 2008; 4:8-25
• “Assessment of Brain Iron and Neuronal Integrity in Patients with Parkinson’s Disease Using Novel MRI Contrasts” S. Michaeli, G. Öz, D. Sorce, M. Garwood, K. Ugurbil, S. Majestic, P. Tuite Movement Disord, 2007; 22:334-340
• “T1? MRI Contrast in the Human Brain: Modulation of the Longitudinal Rotating Frame Relaxation Shutter?Speed During an Adiabatic RF Pulse” S. Michaeli, D. Sorce, C. Springer, Jr., K. Ugurbil, M. Garwood J Magn Reson, 2006; 181:135-147
• “The time-dependence of exchange-induced relaxation during modulated radio frequency pulses” D. Sorce, S. Michaeli, M. Garwood J Magn Reson, 2006; 179:136-139
• “Quantitative T1? and adiabatic Carr-Purcell T2 magnetic resonance imaging of human occipital lobe at 4T” H. Gröhn, S. Michaeli, M. Garwood, R. Kauppinen, O. Gröhn Magn Reson Med, 2005; 54:14-19
• “Exchange-Influenced T2? Contrast in Human Brain Images Measured with Adiabatic RF Pulses” S. Michaeli, H. Gröhn, O. Gröhn, D. J. Sorce, R. Kauppinen, C. S. Springer, K. Ugurbil, M.Garwood Magn Reson Med, 2005; 53:823-829
• “Transverse Relaxation in the Rotating Frame Induced by Chemical Exchange” S. Michaeli, D. J. Sorce, D. Idiyatullin, K. Ugurbil, M. Garwood J Magn Reson, 2004; 169:293-299
• “Product Operator Analysis of the Influence of Chemical Exchange on Relaxation Rates” D. Idiyatullin, S. Michaeli, M. Garwood J Magn Reson, 2004; 171:330-337
• “T2 Relaxation Study of Water, N-acetylaspartate (NAA) and Creatine (Cr) in Human Brains using Hahn and Carr-Purcell Spin-Echoes at 4T and 7T” S. Michaeli, M. Garwood, X. H. Zhu, L. DelaBarre, K. Ugurbil, W. Chen Magn Reson Med, 2002; 47:629-633
• “In-vivo T2 Measurement in the Human Occipital Lobe at 4T and 7T by Carr-Purcell MR Imaging: Detection of Microscopic Susceptibility Contrast” R. Bartha, S. Michaeli, H. Merkle, G. Adriany, P. Anderson, W. Chen, K. Ugurbil, M. Garwood Magn Reson Med, 2002; 47: 742-750
• “Different Excitation and Reception Distributions with a Single-Loop Transmit-Receive Surface Coil near a Head-Sized Spherical Phantom at 300 MHz” C. M. Collins, Q. X. Yang, J. H. Wang, X. Zhang, H. Liu, S. Michaeli, X. H. Zhu, G. Adriany, J. T. Vaughan, P. Anderson, H. Merkle, K. Ugurbil, M. B. Smith, W. Chen Magn Reson Med, 2002; 45:1026-1028
• “Triplet Dynamics of Conformationally Distorted Porphyrins in Isotropic Liquids and Liquid Crystals. Time-Resolved Electron Paramagnetic Resonance Study” S. Michaeli, S. Soffer, H. Levanon and M. Senge J Phys Chem A, 1999; 103:1950-1957
• “Photoinduced Electron Transfer Between N,N,N',N',-tertamethylbenzidine(NTMB). Fourier Transform Electron Paramagnetic Resonance Study” S. Michaeli, V.Meiklyar, H. Levanon, B. Endeward and K. Möbius Res Chem Intermed 1997; 23:505-517
• “Photoexcited Electron Transfer from Triplet Fullerene, 3C60, to Tetracyanoethylene. Fourier Transform Electron Paramagnetic Resonance Study” S. Michaeli, V. Meiklyar, M. Schulz, K. Möbius, H. Levanon J Phys Chem1994; 98:7444-7447.
• “Triplet State and Dynamics of Photoexcited C70” H. Levanon, V. Meiklyar, S. Michaeli, D. Gamlie J Am Chem Soc, 1993; 115:8722-8727
• “Dynamics of 3C60 Probed by Electron Paramagnetic Resonance. Motional Analysis in Isotropic and Liquid Crystalline Matrices” A. Regev, D. Gamliel, V. Meiklyar, S. Michaeli, H. Levanon J Phys Chem, 1993; 97:3671-3679
• “Control of Porphyrin Orientation in Thermotropic Liquid Crystals by Molecular Design. A Time-Resolved EPR Study” S. Michaeli, M. Hugerat, H. Levanon, M. Bernitz, A. Natt, R. Neumann J Am Chem Soc, 1992; 114:3612-3618
• “Paramagnetic States and Dynamics of Photoexcited C60” H. Levanon, V. Meiklyar, A. Michaeli, S. Michaeli, A. Regev J Phys Chem, 1992; 96:6128-6131
• “Controlled Orientation of Porphyrins by Molecular Design in Thermotropic Liquid Crystals. A Time-resolved EPR Study” R. Neumann, M. Hugerat, S. Michaeli, A. Natt, M. Bernitz, H. Levanon Chem Phys Lett, 1991; 182:249-252
• “Solvent Effect in Randomly and Partially Oriented Triplet of the Sapphyrin Dication. Optical and Fast EPR-Magnetophotoselection Measurements” A. Regev, S. Michaeli, H. Levanon, M. Cyr, J. L. Sessler J Phys Chem, 1991; 95:9121-9129
• “The Photoinduced Triplet State of Sapphyrin Dication. Unusual Spin Alignment in Monomers and Spin Delocalisation in Dimers” H. Levanon, A. Regev, S. Michaeli, T. Galili, M. Cyr, J. L. Sessler Chem Phys Lett, 1990; 174:235-240