A hybrid strategy for correcting geometric distortion in echo-planar images

作者：Gelman Neil^*; Silavi Ally; Anazodo Udunna

来源：Magnetic Resonance Imaging, 2014, 32(5): 590-593.

DOI：10.1016/j.mri.2014.02.011

• Geometric distortion correction
• Echo planar imaging
• Reverse phase encode gradient acquisition
• Field mapping
• Diffusion weighted imaging

A hybrid strategy for geometric distortion correction of echo-planar images is demonstrated. This procedure utilizes standard field mapping for signal displacement correction and the so-called reverse gradient acquisition for signal intensity correction. (The term reverse gradient refers to an acquisition of two sets of echo-planar images with phase encoding gradients of opposite polarity.) The hybrid strategy is applied to human brain echo-planar images acquired with and without diffusion-weighting. A comparison of the hybrid distortion corrected images to those corrected with standard field mapping only demonstrates much better performance of the hybrid method. A variant of the hybrid method is also demonstrated which requires the acquisition of only one pair of opposite polarity images within a set of images.

• 出版日期2014-6