High-T/sub c/ SQUIDs for low-field NMR and MRI of room temperature samples

Schlenga, K.; McDermott, Robert; Clarke, John; Souza, Ricardo Emmanuel de; Wong-Foy, A.; Pines, Alexander

doi:10.1109/77.784006

Cited by 10 publications

(9 citation statements)

References 17 publications

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“…In addition to these experiments, it was impressively demonstrated that one SQUID detector was even sensitive enough to observe an extremeIy weak thermal proton signal (signal-to-noise: N2: 1) from a proton-rich mineral oil sample at 20 G in a single scan [261], and could obtain similar signals in thousands of scans at Earth's field. [261]. Note that the gradient coils are arranged parallel to static field coils, which in turn are arranged perpendicular to the audio-frequency (af) coils used to pulse on the nuclear spins.…”

Section: Room-temperature Experimentsmentioning

confidence: 99%

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Nuclear Magnetic Resonance of Laser-Polarized Noble Gases in Molecules, Materials, and Organisms

Goodson

2002

Journal of Magnetic Resonance

417

246

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Section: Room-temperature Experimentsmentioning

confidence: 99%

“…Naturally, this temperature regime prohibits many of the types of experiments that could be performed, particularly ones involving living organisms. However, A high-TC SQUID dewared to permit room-temperature experiments has recently been developed [261]. The high-TC SQUID apparatus is shown schematically in Fig.…”

Section: Room-temperature Experimentsmentioning

confidence: 99%

Nuclear Magnetic Resonance of Laser-Polarized Noble Gases in Molecules, Materials, and Organisms

Goodson

2002

Journal of Magnetic Resonance

417

246

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“…SQUID are used in ULF MRI with microtesla-range magnetic fields for the image that has been pioneered by [121,122]. The low signal-to-noise ratio is partially compensated for by pre-polarizing the sample in a field up to 200 mT and using SQUID for signal detection.…”

Section: Superconducting Quantum Interference Devices (Squid)mentioning

confidence: 99%

Detection of magnetic nanomaterials in molecular imaging and diagnosis applications

Yao

2014

Nanotechnology Reviews

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Advances in bionanotechnology promise to allow medical diagnosis and therapy through the channel of molecular imaging. Combining biological science and modern detection techniques, molecular imaging has the ability to penetrate biomedical processes at the molecular and cellular level. Magnetic nanoparticles (MNP), broadly defined as particles of tens of nm to approximately 2 μm in diameter in this review, are playing an increasingly important role in molecular imaging. They act as contrast agents to remarkably enhance the signal. The precise determination of the position and quantity of MNP is critical for these applications. This review describes the advances in the development of detection techniques for magnetic particles used in molecular imaging and diagnosis. The techniques are categorized as high magnetic field techniques and low magnetic field techniques. The high-field studies focus on magnetic resonance imaging (MRI). The ultralow-field (ULF) studies include several of the most recent techniques: giant magnetoresistance sensors, superconducting quantum interference devices, atomic magnetometers, and magnetic particle imaging. The advantages and disadvantages of each method are discussed.

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“…The intensity of the NMR signal from a given part of the sample depends on its position relative to the magnetometer. Therefore our imaging method involves both frequency encoding and position encoding of the spins in our sample 27 . Our earliest two-dimensional imaging experiments involved a simple scheme in which the sample is placed on the top of the SQUID magnetometer and sequentially rotated in a magnetic field gradient applied parallel to the plane of the magnetometer.…”

Section: Nmr/mrimentioning

confidence: 99%

“…where φ(x, y, z) describes the contribution of an ensemble of dipoles located at the coordinates (x, y, z) to the total magnetic flux through the magnetometer 27 , ρ(x, y, z) is the spin density at (x,y,z), and k = γGt/2π, where γ is the gyromagnetic ratio; the center of the magnetometer defines the origin in space (0,0,0), and the xz plane is taken to coincide with the plane of the magnetometer. Therefore the function signal (k,α) is intrinsically defined in a polar raster.…”

Section: Nmr/mrimentioning

confidence: 99%

NMR and MRI obtained with high transition temperature dc SQUIDs

Souza¹,

Schlenga²,

Wong-Foy³

et al. 1999

J. Braz. Chem. Soc.

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Usando um espectrômetro baseado em um SQUID (dispositivo supercondutor de interferência quântica), de alta temperatura de transição, polarizado continuamente, medimos sinais de ressonân-cia magnética nuclear (RMN) de várias amostras a temperatura ambiente em campos magnéticos na faixa entre 0,05 mT e 2 mT. É possível observar sinais de prótons em uma amostra com 1 mL de óleo mineral em 2 mT com apenas uma aquisição. A sensibilidade do sistema também permite a detecção de RMN de prótons em um campo magnético tão baixo quanto 0,059 mT, o qual é comparável ao campo da Terra. Estes resultados tornam possíveis vários outros experimentos em imagens por ressonância magnética nuclear. Apresentamos uma imagem em duas dimensões obtida a temperatura ambiente em um campo magnético de 2 mT a partir de um padrão com uma estrutura interna preenchida com óleo mineral.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-Tc dc SQUID (high transition temperature dc 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'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.

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High-T/sub c/ SQUIDs for low-field NMR and MRI of room temperature samples

Cited by 10 publications

References 17 publications

Nuclear Magnetic Resonance of Laser-Polarized Noble Gases in Molecules, Materials, and Organisms

Nuclear Magnetic Resonance of Laser-Polarized Noble Gases in Molecules, Materials, and Organisms

Detection of magnetic nanomaterials in molecular imaging and diagnosis applications

NMR and MRI obtained with high transition temperature dc SQUIDs

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