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Title: Microtesla magnetic resonance imaging with a superconducting quantum interference device

Abstract

We have constructed a magnetic resonance imaging (MRI) scanner based on a dc Superconducting QUantum Interference Device (SQUID) configured as a second-derivative gradiometer. The magnetic field sensitivity of the detector is independent of frequency; it is therefore possible to obtain high-resolution images by prepolarizing the nuclear spins in a field of 300 mT and detecting the signal at 132 fYT, corresponding to a proton Larmor frequency of 5.6 kHz. The reduction in the measurement field by a factor of 10,000 compared with conventional scanners eliminates inhomogeneous broadening of the nuclear magnetic resonance lines, even in fields with relatively poor homogeneity. The narrow linewidths result in enhanced signal-to-noise ratio and spatial resolution for a fixed strength of the magnetic field gradients used to encode the image. We present two-dimensional images of phantoms and pepper slices, obtained in typical magnetic field gradients of 100 fYT/m, with a spatial resolution of about 1mm. We further demonstrate a slice-selected image of an intact pepper. By varying the time delay between removal of the polarizing field and initiation of the spin echo sequence we acquire T1-weighted contrast images of water phantoms, some of which are doped with a paramagnetic salt; here, T1 is the nuclearmore » spin-lattice relaxation time. The techniques presented here could readily be adapted to existing multichannel SQUID systems used for magnetic source imaging of brain signals. Further potential applications include low-cost systems for tumor screening and imaging peripheral regions of the body.« less

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Director. Office of Science. Office of Basic Energy Sciences (US)
OSTI Identifier:
840330
Report Number(s):
LBNL-55012
R&D Project: 508601; TRN: US200510%%83
DOE Contract Number:  
AC03-76SF00098
Resource Type:
Journal Article
Journal Name:
PNAS
Additional Journal Information:
Journal Volume: 101; Journal Issue: 21; Other Information: Submitted to PNAS: Volume 101, No.21; Journal Publication Date: 05/25/2004; PBD: 15 Mar 2004
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; MAGNETIC FIELDS; MAGNETIC RESONANCE; NEOPLASMS; NUCLEAR MAGNETIC RESONANCE; PEPPERS; PHANTOMS; PROTONS; REMOVAL; SENSITIVITY; SIGNAL-TO-NOISE RATIO; SPATIAL RESOLUTION; SPIN ECHO; SPIN-LATTICE RELAXATION; SQUID DEVICES; TIME DELAY; MAGNETIC RESONANCE IMAGING MRI SQUID NMR LOW-FIELD

Citation Formats

McDermott, Robert, Lee, SeungKyun, ten Haken, Bennie, Trabesinger, Andreas H, Pines, Alexander, and Clarke, John. Microtesla magnetic resonance imaging with a superconducting quantum interference device. United States: N. p., 2004. Web. doi:10.1073/pnas.0402382101.
McDermott, Robert, Lee, SeungKyun, ten Haken, Bennie, Trabesinger, Andreas H, Pines, Alexander, & Clarke, John. Microtesla magnetic resonance imaging with a superconducting quantum interference device. United States. doi:10.1073/pnas.0402382101.
McDermott, Robert, Lee, SeungKyun, ten Haken, Bennie, Trabesinger, Andreas H, Pines, Alexander, and Clarke, John. Mon . "Microtesla magnetic resonance imaging with a superconducting quantum interference device". United States. doi:10.1073/pnas.0402382101. https://www.osti.gov/servlets/purl/840330.
@article{osti_840330,
title = {Microtesla magnetic resonance imaging with a superconducting quantum interference device},
author = {McDermott, Robert and Lee, SeungKyun and ten Haken, Bennie and Trabesinger, Andreas H and Pines, Alexander and Clarke, John},
abstractNote = {We have constructed a magnetic resonance imaging (MRI) scanner based on a dc Superconducting QUantum Interference Device (SQUID) configured as a second-derivative gradiometer. The magnetic field sensitivity of the detector is independent of frequency; it is therefore possible to obtain high-resolution images by prepolarizing the nuclear spins in a field of 300 mT and detecting the signal at 132 fYT, corresponding to a proton Larmor frequency of 5.6 kHz. The reduction in the measurement field by a factor of 10,000 compared with conventional scanners eliminates inhomogeneous broadening of the nuclear magnetic resonance lines, even in fields with relatively poor homogeneity. The narrow linewidths result in enhanced signal-to-noise ratio and spatial resolution for a fixed strength of the magnetic field gradients used to encode the image. We present two-dimensional images of phantoms and pepper slices, obtained in typical magnetic field gradients of 100 fYT/m, with a spatial resolution of about 1mm. We further demonstrate a slice-selected image of an intact pepper. By varying the time delay between removal of the polarizing field and initiation of the spin echo sequence we acquire T1-weighted contrast images of water phantoms, some of which are doped with a paramagnetic salt; here, T1 is the nuclear spin-lattice relaxation time. The techniques presented here could readily be adapted to existing multichannel SQUID systems used for magnetic source imaging of brain signals. Further potential applications include low-cost systems for tumor screening and imaging peripheral regions of the body.},
doi = {10.1073/pnas.0402382101},
journal = {PNAS},
number = 21,
volume = 101,
place = {United States},
year = {2004},
month = {3}
}