Magnetic microstructures for magnetic resonance imaging

Patent metadata

Field	Value
Publication number	US-10188755-B2
Application number	US-201514739802-A
Country	US
Kind code	B2
Filing date	Jun 15, 2015
Priority date	Apr 18, 2008
Publication date	Jan 29, 2019
Grant date	Jan 29, 2019

Abstract

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 2 * contrast agents that have a significantly higher magnetic moment compared to similarly-sized existing MRI contrast agents.

First claim

The invention claimed is:

1. A magnetic resonance contrast agent comprising one or a plurality of contrast structures, wherein each contrast structure consists of a single wall consisting of a magnetic material arranged as a substantially cylindrical magnetic structure with a length-to-diameter ratio between 0.8 and 1.6, wherein each contrast structure has a maximum dimension between about 10 nm and about 100 μm, wherein each contrast structure defines an axially extending hollow region therethrough, and wherein the hollow region encompasses a spatially extended region contained within a near-field region of the contrast structure over which the structure on its own or in conjunction within an applied magnetic field results in a substantially homogeneous field, such that nuclear magnetic moments of a second material when arranged within said spatially extended region precess at a characteristic Larmor frequency, whereby the magnetic resonance contrast agent, combined with the second material, induces a characteristic magnetic resonance signal of the magnetic material.

2. The magnetic contrast agent of claim 1 , wherein the contrast structures are dispersed in a medium.

3. The magnetic contrast agent of claim 2 , wherein the medium is a liquid.

4. The magnetic resonance contrast agent of claim 1 , wherein each contrast structure has a length-to-diameter ratio of 1.

5. The magnetic resonance contrast agent of claim 1 , wherein each contrast structure permits a fluid to at least one of flow through and diffuse through at least a portion of the spatially extended region of a local magnetic field created by the contrast structure.

6. The magnetic resonance contrast agent of claim 1 , wherein each contrast structure has a maximum dimension between about 50 nm and about 10 μm.

7. A method of performing magnetic resonance imaging, comprising:
(a) providing the magnetic resonance contrast agent of claim 1 dispersed in a medium;
(b) illuminating the magnetic resonance contrast agent with an excitatory electromagnetic pulse; and
(c) detecting electromagnetic radiation emitted from the magnetic resonance contrast agent with a detection system.

8. The method of claim 7 , wherein the medium is a liquid.

Assignees

• Us Health
• Us Commerce

Inventors

• Zabow Gary
• Dodd Stephen
• Koretsky Alan
• Moreland John

Classifications

• G01R33/56325

  Cine imaging · CPC title

• G01R33/5635

  Angiography, e.g. contrast-enhanced angiography [CE-MRA] or time-of-flight angiography [TOF-MRA] · CPC title

• G01R33/563

  of moving material, e.g. flow contrast angiography · CPC title

• Y10T428/2982

  Particulate matter [e.g., sphere, flake, etc.] · CPC title

• A61K49/18

  characterised by a special physical form, e.g. emulsions, microcapsules, liposomes · CPC title