susceptibility artifact
Signal distortion in MRI images caused by magnetic field inhomogeneities near air-tissue boundaries, particularly problematic in orbitofrontal and temporal regions.
Full Definition
Susceptibility artifacts are signal dropouts and geometric distortions that occur in MRI images when tissues with different magnetic susceptibilities are adjacent to each other, such as brain tissue near air-filled sinuses. These artifacts are especially pronounced in echo-planar imaging sequences commonly used in fMRI studies. The orbitofrontal cortex and anterior temporal lobes are particularly affected due to their proximity to the sinuses and ear canals. Neuroinformatics workflows must account for these artifacts through specialized acquisition parameters, shimming procedures, or post-processing correction techniques to ensure accurate data interpretation.
Usage
Usage note: Often hyphenated as 'susceptibility-artifact' in technical specifications but written as two words in general neuroimaging literature.
In Context
- "The orbitofrontal cortex showed significant susceptibility artifact that required specialized acquisition sequences." — fMRI study protocol
- "Quality control procedures must identify scans with excessive susceptibility artifact before statistical analysis." — neuroimaging pipeline documentation