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Simultaneous Detection of Nuclear Magnetic Resonance and Biomagnetic Signals at Ultra-low Magnetic Fields| old_uid | 1540 |
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| title | Simultaneous Detection of Nuclear Magnetic Resonance and Biomagnetic Signals at Ultra-low Magnetic Fields |
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| start_date | 2006/09/14 |
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| schedule | 11h |
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| online | no |
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| summary | Anatomical imaging of the brain is typically generated using high magnetic fields (several Tesla). Separately, the brain's electrical activity generates extremely low magnetic fields that are measurable by ultrasensitve detectors. Combining the two methods was generally thought impossible until recently when magnetic fields one million times weaker than normal were used to demonstrate nuclear magnetic resonance (NMR). NMR and magnetic resonance imaging (MRI) at ultra-low magnetic fields (ULF, fields of ~microT) have several advantages over their counterparts at higher magnetic fields. These include narrow line widths, the possibility of novel imaging schemes such as T1 weighted images, and reduced system cost and complexity. In addition, ULF NMR/MRI with superconducting quantum interference devices (SQUIDs) is compatible with simultaneous measurements of biomagnetic signals (magnetoencephalography - MEG), a capability conventional systems cannot offer.
This overview talk will be aimed at the introductory level of understanding in NMR and MEG, briefly reviewing the underlying concepts, and how SQUIDs can measure both simultaneously. We discuss the signal processing used to separate and indentify the key components in the measured signals, and we present novel experimental demonstrations of these measurements in heart, muscle, and brain. We then discuss the "Holy Grail" of research in this field, which is to show that the anatomical and functional signals may interact, which would lead to new breakthroughs in accurate modeling of neural function, and we show some tantalizing preliminary results in this direction.
We conclude with recent results presented at Biomag 2006 showing MR images of the human hand, generated at a measurement field of only 50 microTesla, i.e. equal to the Earth's magnetic field. |
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| oncancel | Ajout |
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| responsibles | Béranger |
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