Quick Overview

Zipper artifacts appear as dashed lines. There are various causes for this MRI artifact.
Most of zipper artifacts result from inhomogeneities of the magnetic field caused by interferences with radio frequency from various sources ('your radio is working in the scanner room means your shielding is not working'). Software and equipment problems can also cause zipper lines in both directions.

Scanning room door during the acquisition of images is closed, shielding is working, and all disturbing devices are removed?

See also Room Shielding, Active Shielding, Radio Frequency Shielding.

Quick Overview
Please note that there are different common names for this artifact.

This artifact appears as a bright spot (or zipper line) in the image center. Central point artifacts are caused by a DC offset in the hardware. MRI scanners normally offer a software compensation (DC correction, baseline correction) for prevention.

Take care for a constant temperature. If the problem increases or keeps on existing, it should be addressed to the service.