Multilayered RF Coil System for Improving Transmit B1 Field Homogeneity in High-Field MRI

Available for licensing and commercial development is a multilayered radio-frequency (RF) coil system for improving the transmit B1 field homogeneity for magnetic resonance imaging (MRI) at high field strengths. The current invention aims at manipulating the inhomogeneous profile of the transmit B1 field, which causes MR images to become less uniform as the magnetic field strength is increased, by utilizing an inner array of RF elements (e.g. surface coils) within and coupled to an outer transmit unit (e.g. a birdcage coil or other volume coil). Improvement in B1 field homogeneity is achieved by tuning the surface coils of the inner layer to an appropriate resonant frequency and then passively coupling them to the outer-layer volume coil. Furthermore, the amount of coupling is determined by the intrinsic properties of the transmit unit and can be adjusted accordingly. The current design provides an effective approach for reducing B1 field homogeneity at high fields and can be implemented without the need for independent RF channels, thereby reducing MRI system complexity. Furthermore it can be readily implemented on existing MRI coil systems by detuning surface coils rather than decoupling them during the transmit phase.

Potential Commercial Applications: Competitive Advantages:
  • High-Field MRI
  • Improvement of MR Image Uniformity

Development Stage:
The technology is ready to be used and requires only testing in humans for development.


Alan Koretsky (NINDS)  ➽ more inventions...

Jozef (Jeff) Duyn (NINDS)  ➽ more inventions...

Shumin Wang (NINDS)  ➽ more inventions...

Hellmut Merkle (NINDS)  ➽ more inventions...

Intellectual Property:
US Pat: 8,125,225 issued 2012-02-28
PCT Application No. PCT/US2008/001911 filed on 2008-02-13
US Application No. 12/449,514 filed on 2009-08-12

S Wang and JH Duyn, "Three-Dimensional Automatic Mesh Generation for Hybrid Electromagnetic Simulations", IEEE Antennas and Propagation Magazine, Vol. 51, pp. 71-85, April 2009.
H Merkle, J Murphy-Boesch, S Wang, P van Gelderen, AP Koretsky, and JH. Duyn, "Graded Transmit B1 Field Correction at 7T using Tunable Inner Elements", ISMRM High-field Workshop, Rome, Italy, October 2008.
H Merkle, S Wang, P van Gelderen, TQ. Li, J Murphy-Boesch, AP Koretsky, and JH Duyn, "B1 Transmit Field Correction at 7T using Coupled Inner Elements", ISMRM 2008, Toronto, Canada, May 2008.
S Wang, H Merkle, AP Koretsky, and JH Duyn, "Improving High-Field Transmit B1 Field Homogeneity Using Coupled Inner Elements", 15th Scientific Meeting and Exhibition, International Society for Magnetic Resonance in Medicine, Berlin, Germany, May 2007.

Collaboration Opportunity:

The Laboratory of Functional and Molecular Imaging (LFMI) at the National Institute of Neurological Disorders and Stroke (NINDS) is seeking statements of capability or interest from parties interested in collaborative research to further develop, evaluate, or commercialize MRI applications that aim to provide novel functional and molecular imaging techniques to study brain structure and function. Please contact Laurie Arrants at or 301-435-3112 for more information.

Licensing Contact:
Susan Ano, Ph.D.
Phone: 301-435-5515

OTT Reference No: E-020-2007-0
Updated: Sep 22, 2015