central point artifact

The central point artifact is a focal dot of increased signal in the center of an image. It is caused by a constant offset of the DC voltage in the receiver. After Fourier transformation, this constant offset gives the bright dot in the center of the image as shown in the diagram.

The axial MRI image of the head shows a central point artifact projecting in the pons in the center of the image.

Correction and prevention
  • repeating the sequence may get rid of the artifact.
  • maintain a constant temperature in scanner and equipment room for receiver amplifiers.
  • software to estimate DC offset and adjust the data in k-space.
  • call service engineer for recalibration
Imaging technology