Unmet Need: Chemical exchange saturation transfer (CEST) imaging is a relatively new contrast mechanism for MRI exploiting exchange-based magnetization transfer (MT) between solute and water protons. Although it has huge potential for developing noninvasive agents for cell labeling and other applications, when applying the method in vivo or even in phantoms, often results in regions of artifactual intensities. This is due to the fact that CEST images depend on exact knowledge of the water resonance frequency in each image volume element (voxel) and are extremely sensitive to magnetic inhomogeneties.
Technology: The invention is a post-processing method called Water Saturation Shift Referencing (or WASSR) which can provide exact information regarding the center water frequency in each image volume element and using this information corrections for spatial magnetic field variations can be made on a voxel-by-voxel basis. Furthermore, traditional MRI field mapping is unable to solve this issue because the determination of the exact CESST center frequency of water is needed for at least one voxel.
Looking for Partners: The information provided from the WASSR method allows for the generation of CEST images with minimal field-inhomogeneity based intensity artifacts. Solving this problem clears the way for CEST to become a practical MRI method.
Patent Status: Granted US Patent 8,536,866
