What is susceptibility artifact?

Susceptibility artifact refers to image distortion in magnetic resonance imaging (MRI) caused by variations in magnetic susceptibility between different tissues. This results in signal loss, distortion, and dark regions in the image, particularly in areas near air-tissue interfaces or metallic objects, making it difficult to interpret the affected images accurately. Special imaging techniques, such as susceptibility-weighted imaging (SWI), can be used to minimize or exploit these artifacts for diagnostic purposes.