WARF: P130370US01

Robust Magnetic Field Map Estimation Improves MRI Fat-Water Separation


Scott Reeder, Nathan Artz, Samir Sharma

The Wisconsin Alumni Research Foundation (WARF) is seeking commercial partners interested in developing a method for performing chemical species (e.g., fat-water) separation by using a more robust estimate of the magnetic field map.
OVERVIEWIn magnetic resonance imaging (MRI), the main magnetic field is symbolized B0. Accurately estimating a B0 field map is critical to distinguishing different chemical species like water and fat. If the B0 field map is estimated accurately, then water and fat signals can be separated using a straightforward technique.

Conversely, inaccurate estimation of the B0 field map can lead to “swaps” of the water and fat signals. This is a problem because the radiologist may be unable to discern true pathology from an artifact in the image. As a result, important anatomical findings may be completely missed.
THE INVENTIONUW–Madison researchers have developed a method to improve the robustness of chemical species separation in MRI. Their approach uses an object-based initial estimate of the B0 field map.

More specifically, an MRI system scans a subject to acquire k-space data at different echo times and subsequently reconstructs images. The pixel values of these images are used to estimate a distribution of magnetic susceptibility values found in the subject. A magnetic field inhomogeneity map is estimated from the magnetic susceptibility distribution, and chemical species separation (e.g., fat-water separation) then can be performed.

The new approach is intended to improve the robustness of existing techniques for chemical shift encoded chemical species separations.
  • Relevant to any complex-based chemical species separation technique
  • Software for MRI, susceptibility-weighted imaging and quantitative susceptibility mapping
  • Especially useful for clinical imaging of regions prone to fat-water swaps, including the liver, brachial plexus and lower extremities
  • Achieves more robust chemical species separation
  • Reduces computational burden
  • Helps correct for image distortions and generate magnetic field shimming values
STAGE OF DEVELOPMENTThe researchers estimate the new method could save up to 95 percent of reconstruction time compared to conventional techniques, as well as augment existing water-fat swap solutions.
Contact Information
For current licensing status, please contact Jeanine Burmania at or 608-960-9846.
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