What is the appearance of sampling artefacts in MRI?

Sampling artifacts in MRI typically manifest as parallel lines of varying signal intensity, particularly in areas adjacent to high-contrast boundaries. This occurs due to the limitations of the sampling frequency during data acquisition. When the frequency of the data points does not adequately capture the rapid changes in signal that occur at these high-contrast interfaces, it can result in these conspicuous patterns.

These artifacts can lead to misinterpretation of an image, as they may mimic pathology or distort the appearance of actual anatomical structures. The presence of such parallel lines signifies that the MRI system is encountering difficulties in accurately capturing the signal data for those areas.

High signal intensity lines near anatomical boundaries are not a definitive characteristic of sampling artifacts; rather, they can be indicative of other phenomena such as chemical shift artifacts. Random noise throughout the image typically suggests issues with the signal-to-noise ratio rather than sampling. A uniform low signal intensity across the image might suggest the influence of other factors like inadequate coil sensitivity or saturation effects rather than being specifically related to sampling artifacts. Therefore, the description of parallel lines adjacent to high contrast boundaries aligns accurately with the recognized behavior of sampling artifacts in MRI.