susceptibility distortion
Geometric distortion in MRI images caused by local magnetic field inhomogeneities, particularly prominent at tissue-air interfaces.
Full Definition
Susceptibility distortion occurs when differences in magnetic susceptibility between tissues create local magnetic field variations that cause spatial warping of the acquired image. This artifact is especially problematic in echo planar imaging sequences commonly used for functional MRI, where it can cause signal dropout and geometric distortion in regions like the orbitofrontal cortex and temporal poles. Understanding this concept is crucial for editors evaluating neuroimaging studies, as inadequate correction can affect the accuracy of brain activation localization and statistical analyses.
Usage
Usage note: Often used interchangeably with 'susceptibility artifact' in neuroimaging contexts.
In Context
- "Susceptibility distortion was corrected using field maps acquired prior to the functional runs." — neuroimaging methods section
- "The anterior temporal regions showed significant susceptibility distortion requiring specialized correction algorithms." — technical neuroimaging report