Real-Time Correction of Magnetic Field Fluctuations in MRI
Description of Invention:
Available for licensing is a new MRI technique that will markedly improve the diagnostic potential of the rendered images. This is a method for applying real-time corrections to prevent image distortions caused by field variations that are due to the patient's respiratory cycle or instrument instability. These field variations reduce the B0 homogeneity in a non-uniform and spatially-dependent manner. They may lead to a variety of image artifacts such as ghosting and blurring. This method provides a way of calculating the correct electrical currents that must be applied to a set of gradients and shims, smaller magnets that are used to make fine-tune adjustments to the magnetic field in a spatially-dependent manner. As the MRI subject breathes, changes in the B0 field occur. During a brief training session, the amplitude of these changes as a function of chest motion is recorded in a phase map. Similarly, changes in B0 as a function of chest motion is recorded in a phase map. Similarly, changes in B0 as a function of current intensity is available from calibration data containing B0 as a function of coil current. As the subject undergoes a scan, compensatory currents are applied to the x, y, or z axis of the gradients and the shims coils in order to correct for the effect of respiration on the B0 homogeneity. The shim values can be updated every 10 to 80 milliseconds during an experiment. This method results in a substantial decrease in artifacts that can obscure the overall image quality. It can be used for virtually all types of scans and MRI instruments.
Applications:
Real-time correction of magnetic fluctuations in MRI experiments
Improved MRI image precision
Market:
MRI manufacturers, hospitals, medical research centers, and universities
Development Status:
The technology is ready to be used and requires no further testing or development.
Inventors:
Jozef H. Duyn (NINDS) Peter van Gelderen (NINDS) et al.
Patent Status:
DHHS Reference No. E-085-2006/0 --
U.S. Provisional Application No. 60/781,246 filed 10 Mar 2006
PCT Application No. PCT/US2007/005826 filed 06 Mar 2007
Relevant Publication: P van Gelderen, JA de Zwart, P Starewicz, RS Hinks, JH Duyn. Real time shimming for compensation of respiration induced field changes. Proceedings ISMRM 2006, page 752.
Licensing Status: This technology is no longer available for licensing.
For Additional Information Please Contact: John Stansberry Ph.D.
NIH Office of Technology Transfer
6011 Executive Boulevard, Suite 325
Rockville, MD 20852-3804
Phone: (301)435-5236
Email: stansbej@mail.nih.gov
Fax: (301) 402-0220
