Abstract: The present invention provides a method of handling rapid phase aliasing in magnetic resonance images arising from local magnetic susceptibility differences. The methods of the present invention can be used to estimate the field effects within an object arising from the interfaces of regions having differences in magnetic susceptibilities, and to subtract out the resulting phase from the original or source phase data prior to any further phase processing. The methods of the present invention also include a process of accurately determining the susceptibility values of multiple voxel regions based on the geometry of such regions.
Type:
Grant
Filed:
April 18, 2008
Date of Patent:
August 24, 2010
Assignee:
MR Innovations, Inc.
Inventors:
E. Mark Haacke, Jaladhar Neelavalli, Yu-Chung Norman Cheng
Abstract: Segmented echo planar nuclear magnetic resonance imaging is performed using an iterative correction method that corrects or suppresses geometric distortion in the image domain caused by off-resonance phase discontinuities in the phase encoding direction. The iterative correction method can be performed in a single scan by providing extra gradients in the pulse sequence to generate an extra transverse magnetization echo from the pulse. Additionally, the iterative correction method can be performed using a separate non-segmented double-echo scan in combination with data obtained using a conventional segmented echo planar imaging pulse sequence.