Abstract
Neuroscience methods entailing in vivo measurements of brain activity have greatly contributed to our understanding of brain function for the past decades, from the invasive early studies in animals using single-cell electrical recordings, to the noninvasive techniques in humans of scalp-recorded electroencephalography (EEG) and magnetoencephalography (MEG), positron emission tomography (PET), and, most recently, blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI). A central objective of these techniques is to measure neuronal activities with high spatial and temporal resolution. Each of these methods, however, has substantial limitations in this regard. Single-cell recording is invasive and only typically records cellular activity in a single location; EEG/MEG cannot generally provide accurate and unambiguous delineations of neuronal activation spatially; and the most sophisticated BOLD-based fMRI methods are still fundamentally limited by their dependence on the very slow hemodynamic responses upon which they are based. Even the latest neuroimaging methodology (e.g., multimodal EEG/fMRI) does not yet unambiguously provide accurate localization of neuronal activation spatially and temporally. There is hence a need to further develop noninvasive imaging methods that can directly image neuroelectric activity and thus truly achieve a high temporal resolution and spatial specificity in humans. Here, we discuss the theory, implementation, and potential utility of an MRI technique termed Lorentz effect imaging (LEI) that can detect spatially incoherent yet temporally synchronized, minute electrical activities in the neural amplitude range (microamperes) when they occur in a strong magnetic field. Moreover, we demonstrate with our preliminary results in phantoms and in vivo, the feasibility of imaging such activities with a temporal resolution on the order of milliseconds.
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K.K. Kwong, J.W. Belliveau, D.A. Chesler, I.E. Goldberg, R.M. Weisskoff, B.P. Poncelet, D.N. Kennedy, B.E. Hoppel, M.S. Cohen, R. Turner, H.-M. Cheng, T.J. Brady, B.R. Rosen, Dynamic magnetic resonance imaging of human brain activity during primary sensory stimulation, Proc. Natl. Acad. Sci. USA 89 (1992) 5675–5679.
P.A. Bandettini, E.C. Wong, R.S. Hinks, R.S. Tikofski, J.S. Hyde, Time course EPI of human brain function during task activation, Magn. Reson. Med. 25 (1992)390–397.
S. Ogawa, D.W. Tank, R. Menon, J.M. Ellermann, S.G. Kim, H. Merkle, K. Ugurbil, Intrinsic signal changes accompanying sensory stimulation: functional brain mapping with magnetic resonance imaging, Proc. Natl. Acad. Sci. USA 89 (1992) 5951–5955.
S. Ogawa, R.S. Menon, D.W. Tank, D.G. Kim, H. Merkle, J.M. Ellermann, K. Ugurbil, Functional brain mapping by blood oxygenation level-dependent contrast magnetic resonance imaging. A comparison of signal characteristics with a biophysical model, Biophys. J. 64 (1993) 803–812.
S.G. Kim, W. Richter, K. Ugurbil, Limitations of temporal resolution in functional MRI, Magn. Reson. Med. 37 (1997) 631–636.
R.L. Buckner, Event-related fMRI and the hemodynamic response, Hum. Brain Mapp. 6 (1998) 373–377.
M. Joy, G. Scott, M. Henkelman, In vivo detection of applied electric currents by magnetic resonance imaging, Magn. Reson. Imaging 7 (1989) 89–94.
J. Bodurka, A. Jesmanowicz, J.S. Hyde, H. Xu, L. Estkowski, S.J. Li, Current-induced magnetic resonance phase imaging, J. Magn. Reson. 137 (1999) 265–271.
J. Bodurka, P.A. Bandettini, Toward direct mapping of neuronal activity: MRI detection of ultraweak, transient magnetic field changes, Magn. Reson. Med. 47 (2002)1052–1058.
D. Konn, P. Gowland, R. Bowtell, MRI detection of weak magnetic fields due to an extended current dipole in a conducting sphere: A model for direct detection of neuronal currents in the brain, Magn. Reson. Med. 50 (2003) 40–49.
H. Kamei, K. Iramina, K. Yoshikawa, S. Ueno, Neuronal current distribution imaging using magnetic resonance, IEEE Trans. Magn. 35 (1999) 4109–4111.
J. Xiong, P.T. Fox, J.H. Gao, Directly mapping magnetic field effects of neuronal activity by magnetic resonance imaging, Hum. Brain Mapp. 20 (2003) 41–49.
R. Chu, J.A. de Zwart, P. van Gelderen, M. Fukunaga, P. Kellman, T. Holroyd, J.H. Duyn, Hunting for neuronal currents: Absence of rapid MRI signal changes during visual-evoked response, Neuroimage 23 (2004) 1059–1067.
M. Bianciardi, F. Di Russo, T. Aprile, B. Maraviglia, G.E. Hagberg, Combination of BOLD-fMRI and VEP recordings for spin-echo MRI detection of primary magnetic effects caused by neuronal currents, Magn. Reson. Imaging 22 (2004)1429–1440.
D. Konn, S. Leach, P. Gowland, R. Bowtell, Initial attempts at directly detecting alpha wave activity in the brain using MRI, Magn. Reson. Imaging 22 (2004)1413–1427.
P.A. Bandettini, N. Petridou, J. Bodurka, Direct detection of neuronal activity with MRI: Fantasy, possibility, or reality?, Appl. Magn. Reson. 29 (2005) 65–88.
N. Petridou, D. Pleaz, A.C. Silva, M. Lowe, J. Bodurka, P.A. Bandettini, Direct magnetic resonance detection of neuronal electrical activity, Proc. Natl. Acad. Sci. USA 103 (2006) 16015–16020.
L.S. Chow, G.G. Cook, E. Whitby, M.N.J. Paley, Investigating direct detection of axon firing in the adult human optic nerve using MRI, Neuroimage 30 (2006) 835–846.
G.E. Hagberg, M. Bianciardi, B. Maraviglia, Challenges for detection of neuronal currents by MRI, Magn. Reson. Imaging 24 (2006) 483–493.
Y. Xue, J.-H. Gao, J. Xiong, Direct MRI detection of neuronal magnetic fields in the brain: Theoretical modeling, Neuroimage 31 (2006) 550–559.
L.S. Chow, G.G. Cook, E. Whitby, M.N.J. Paley, Investigation of MR signal modulation due to magnetic fields from neuronal currents in the adult human optic nerve and visual cortex, Magn. Reson. Imaging 24 (2006) 681–691.
L.M. Parkes, F.P. de Lange, P. Fries, I. Toni, D.G. Norris, Inability to directly detect magnetic field changes associated with neuronal activity, Magn. Reson. Med. 57 (2007) 411–416.
A.W. Song, A.M. Takahashi, Lorentz effect imaging, Magn. Reson. Imaging 19 (2001) 763–767.
T.-K. Truong, J.L. Wilbur, A.W. Song, Synchronized detection of minute electrical currents with MRI using Lorentz effect imaging, J. Magn. Reson. 179 (2006) 85–91.
T.-K. Truong, A.W. Song, Finding neuroelectric activity under magnetic-field oscillations (NAMO) with magnetic resonance imaging in vivo, Proc. Natl. Acad. Sci. USA 103 (2006) 12598–12601.
T.-K. Truong, A. Avram, A. W. Song, Lorentz effect imaging of ionic currents in solutions, J. Magn. Reson. 59 (2008) 221–227.
E.O. Stejskal, J.E. Tanner, Spin diffusion measurements: Spin echoes in the presence of a time-dependent field gradient, J. Chem. Phys. 42 (1965) 288–292.
J. Kimura, Electrodiagnosis in disease of nerve and muscle: Principles and practice, Oxford University Press, Oxford (2001).
Acknowledgments
This work was, in part, supported by the NIH (NS 50329, NS 41328) and NSF (BES 602529).
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© 2008 Humana Press, a part of Springer Science+Business Media, LLC
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Song, A.W., Truong, TK., Woldorff, M. (2008). Dynamic MRI of Small Electrical Activity. In: Hyder, F. (eds) Dynamic Brain Imaging. METHODS IN MOLECULAR BIOLOGY™, vol 489. Humana Press. https://doi.org/10.1007/978-1-59745-543-5_14
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DOI: https://doi.org/10.1007/978-1-59745-543-5_14
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