The United States of America, as Represented by the Secretary, Department of Health and Human Services

Government of the United States of America, as Represented by the Secretary of Commerce

Zabow, Gary

Dodd, Stephen

Koretsky, Alan

Moreland, John

Gary Zabow

Alan Koretsky

Stephen Dodd

John Moreland

John M Moreland

Chunqi Qian

Joe Murphy-Boesch

Jeff Duyn

Joseph A Murphy-Boesch

Shumin Wang

Hellmut Merkic

Stephen John Dodd

The present invention relates to a magnetic resonance structure with a cavity or a reserved space that provides contrast and the additional ability to frequency-shift the spectral signature of the NMR-susceptible nuclei such as water protons by a discrete and controllable characteristic frequency shift that is unique to each MRS design. The invention also relates to nearly uniform solid magnetic resonance T* contrast agents that have a significantly higher magnetic moment compared to similarly-sized existing MRI contrast agents.

Magnetic microstructures for magnetic resonance imaging

A novel MRI-compatible amplifier design uses positive feedback from a low-noise Field-Effect Transistor to amplify the signal current within a resonant NMR coil. The amplified signal current in this low-power circuit produces RF flux can be coupled out to receiving loops positioned externally without significant loss in sensitivity. In other aspects, the amplifier may be remotely powered by external resonant loops, a small non-magnetic battery, or optical power, such that the NMR coil can be positioned during highly invasive procedures such as for surgical resection of tumors in deep-lying tissues to develop high-resolution images.

Negative resistance preamplifier for inductively coupled local MRI coils

The present invention relates to magnetic contrast structures for magnetic resonance imaging, and methods of their use. The contrast structures include magnetic materials arranged as a pair of disk-shaped magnetic components with a space between a circular surface of each disk shape, or a tubular magnetic structure, a substantially cylindrical magnetic structure, a substantially spherical shell-formed magnetic structure, or a substantially ellipsoidal shell-formed structure, each defining a hollow region therein. The space and/or hollow region in the contrast structure creates a spatially extended region contained within a near-field region of the contrast structure over which an applied magnetic field results in a homogeneous field, such that nuclear magnetic moments of a second material when arranged within the spatially extended region precess at a characteristic Larmor frequency, whereby the contrast structure is adapted to emit a characteristic magnetic resonance signal of the magnetic material.

The present invention relates to a magnetic resonance structure with a cavity or a reserved space that provides contrast and the additional ability to frequency-shift the spectral signature of the NMR-susceptible nuclei such as water protons by a discrete and controllable characteristic frequency shift that is unique to each MRS design. The invention also relates to nearly uniform solid magnetic resonance T* contrast agents that have a significantly higher magnetic moment compared to similarly-sized existing MRI contrast agents. The invention also relates to a magnetic resonance sensor that alters it shape in response to a condition of an environment such that the condition may be detected.

An implantable parametric circuit enables local signal amplification and wireless transmission of RF signals in connection with magnetic resonance imaging systems. The parametric circuit detects RF signal detected during magnetic resonance imaging procedure, amplifies the detected RF signal, and transmits the amplified RF signal in a wireless manner to an external pick-up coil. The parametric amplifier is also configured to use another RF signal generated by an external source as the primary power source. As a result, implanted or catheter coils could be used as a wireless signal transducer without the need for a battery or a power connection.

Wirelessly powered magnetic resonance imaging signal amplification system for ingestible devices having L-C mesh circuit

Wirelessly powered magnetic resonance imaging signal amplification system

A magnetic resonance contrast agent has a medium, and a contrast structure dispersed in the medium. The contrast structure comprises a magnetic material arranged to create a local region of a local magnetic field such that nuclear magnetic moments of a material when arranged within the local region precess at a characteristic Larmor frequency about a total magnetic field in the local region while in use, the characteristic Larmor frequency being identifiable with the contrast structure, and the total magnetic field in the local region being a substantially spatially uniform magnetic field.

An apparatus for imaging includes: a main magnet to generate a substantially uniform main Bmagnetic field through an examination region; and a coil system including a first coil layer and a second coil layer disposed substantially parallel to the first coil layer with a defined air gap in a radial direction, the first coil layer including a first coil array, the second coil layer including a second coil array, the first and second coil arrays being coupled and cooperating to selectively produce a prespecified Bmagnetic field within the examination region.

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Bethesda, MD, United States of America

Alan Koretsky