K-Space Tool: Large Central RF Spike
Just a few pixels to the right, and slightly up from the centre of k-space, you should be able to see the RF spike. Because it's so close to the centre, the artefact on the image has a large periodicity; the spike occurred at a point which represents low spatial frequency. The artefact is slightly at an angle because of the position of the spike. The lines of the artefact are angled such that they are normal to a line drawn from the centre of k-space to the RF spike.
Choose from the list below alter k-space.