@article {331,
	title = {Microtesla MRI with a superconducting quantum interference device},
	journal = {Proceedings of the National Academy of Sciences of the United States of America},
	volume = {101},
	year = {2004},
	note = {P Natl Acad Sci USA823ZCTimes Cited:76Cited References Count:29},
	month = {May 25},
	pages = {7857-7861},
	abstract = {<p>MRI scanners enable fast, noninvasive, and high-resolution imaging of organs and soft tissue. The images are reconstructed from NMR signals generated by nuclear spins that precess in a static magnetic field B(0) in the presence of magnetic field gradients. Most clinical MRI scanners operate at a magnetic field B(0) = 1.5 T, corresponding to a proton resonance frequency of 64 MHz. Because these systems rely on large superconducting magnets, they are costly and demanding of infrastructure. On the other hand, low-field imagers have the potential to be less expensive, less confining, and more mobile. The major obstacle is the intrinsically low sensitivity of the low-field NMR experiment. Here, we show that prepolarization of the nuclear spins and detection with a superconducting quantum interference device (SQUID) yield a signal that is independent of B(0), allowing acquisition of high-resolution MRIs in microtesla fields. Reduction of the strength of the measurement field eliminates inhomogeneous broadening of the NMR lines, resulting 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 high-resolution images of phantoms and other samples and T(1)-weighted contrast images acquired in highly inhomogeneous magnetic fields of 132 muT; here, T, is the spin-lattice relaxation time. These techniques 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.</p>
},
	keywords = {system},
	isbn = {0027-8424},
	doi = {Doi 10.1073/Pnas.0402382101},
	url = {<Go to ISI>://WOS:000221652000005},
	author = {McDermott, R. and Lee, S. K. and ten Haken, B. and Trabesinger, A. H. and Pines, A. and Clarke, J.}
}
@article {387,
	title = {NMR and MRI obtained with high transition temperature DC SQUIDs},
	journal = {Journal of the Brazilian Chemical Society},
	volume = {10},
	year = {1999},
	note = {J Brazil Chem Soc259BETimes Cited:11Cited References Count:30},
	month = {Jul-Aug},
	pages = {307-312},
	abstract = {<p>We have measured nuclear magnetic resonance (NMR) signals from several samples at room temperature in magnetic fields ranging from about 0.05 mT to 2 mT using a spectrometer based on a high-T-c de SQUID (high transition temperature de Superconducting QUantum Interference Device). We are able to observe proton signals from 1 mL of mineral oil in 2 mT in a single transient. The sensitivity of this system has also allowed the detection of proton NMR at magnetic fields as low as 0.059 mT, which is comparable to the Earth\&$\#$39;s field. Such results make possible a number of new experiments in magnetic resonance imaging (MRI). We present a two-dimensional image of a phantom filled with mineral oil obtained in a field of 2 mT.</p>
},
	keywords = {system},
	isbn = {0103-5053},
	url = {<Go to ISI>://WOS:000083873500009},
	author = {de Souza, R. E. and Schlenga, K. and Wong-Foy, A. and McDermott, R. and Pines, A. and Clarke, J.}
}
