zipper artifact

In MR imaging, zipper artifact refers to a type of MRI artefact where one or more spurious bands of electronic noise extend perpendicular to the frequency encode direction and is present in all images of a series.      

There are various causes for zipper artifacts in images. Most of them are related to hardware or software problems beyond the radiologist's immediate control.

The zipper artifacts that can be controlled easily are those that occur when the door is open during acquisition of images due to RF entering the scanning room from electronic equipment (e.g. mobile devices or aircraft) and are being picked by the receiver chain of imaging sub-systems.

RF from some radio transmitters will cause zipper artifacts that are oriented perpendicular to the frequency axis of your image. Frequently there is more than one artifact line on an image from this cause corresponding to different radio frequencies. Other equipment and software problems can cause zippers in either axis.

Remedy

• make sure the MR scanner room-door is shut during imaging
• remove all electronic devices from the patient prior to imaging
• if the artifact persists despite all nearby electronic equipment being turned off, it is possible that the RF shielding is compromised
  • this usually occurs at the contacts between the door and the jam and may need to be cleaned or repaired
  • the penetration panel where the cables enter the room is another site to be checked

Differential diagnosis

• herringbone artifact
  • uniform throughout image
  • variable orientation

Siehe auch:

• Artefakte in der Magnetresonanztomographie
• Corduroy-Artefakt

und weiter:

• Grundlagen der Magnetresonanz-Tomographie