SQUID detected NMR and MRI at ultralow fields
AssigneeThe Regents of the University of California
InventorsJohn Clarke, Robert McDermott, Alexander Pines, Andreas Heinz Trabesinger
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Abstract
Nuclear magnetic resonance (NMR) signals are detected in microtesla fields. Prepolarization in millitesla fields is followed by detection with an untuned de superconducting quantum interference device (SQUID) magnetometer. Because the sensitivity of the SQUID is frequency independent, both signal-to-noise ratio (SNR) and spectral resolution are enhanced by detecting the NMR signal in extremely low magnetic fields, where the NMR lines become very narrow even for grossly inhomogeneous measurement fields. MRI in ultralow magnetic field is based on the NMR at ultralow fields. Gradient magnetic fields are applied, and images are constructed from the detected NMR signals.
Claims45
A method for nuclear magnetic resonance (NMR) of a sample in an ambient room temperature environment, comprising:
- prepolarizing nuclear spins in the sample in a millitesla magnetic field;
- detecting nuclear magnetic resonance (NMR) signals from the sample in the ambient room temperature environment in a microtesla magnetic field with an untuned low critical temperature (Tc) superconducting quantum interference device (SQUID) magnetometer.
Apparatus for nuclear magnetic resonance (NMR) of a sample in an ambient room temperature environment, comprising:
- prepolarization coils for providing a millitesla magnetic field for prepolarizing nuclear spins in the sample;
- measurement coils for providing a microtesla magnetic field for detecting nuclear magnetic resonance (NMR) signals from the sample in the ambient room temperature environment;
- an untuned low critical temperature (Tc) superconducting quantum interference device (SQUID) magnetometer for detecting nuclear magnetic resonance (NMR) signals from the sample.
An apparatus for performing magnetic resonance imaging (MRI) and magnetoencephalography (MEG) on a subject in an ambient room temperature environment, the apparatus comprising:
- a) prepolarizing coils for providing a prepolarizing magnetic field for prepolarizing nuclear spins in the subject;
- b) measurement coils for providing a detecting magnetic field for generating nuclear magnetic resonance (NMR) signals in the subject;
- and
- c) an array of superconducting quantum interference devices (SQUIDs) for performing MRI on the subject by forming an image from said NMR signals and for performing MEG on the subject by measuring biomagnetic signals generated within the subject.
Dependencies are inferred from the claim text.