Gibbs ringing (truncation artifact) in MRI
Fine parallel lines next to a sharp edge, such as the cord or the skull. They come from sampling too few lines of k-space.
Truncation (Gibbs ringing)
Fine parallel lines next to sharp high-contrast edges. In the spinal cord it can mimic a syrinx; in the knee it can mimic a meniscal tear.
A sharp edge needs infinitely many spatial frequencies; a finite matrix truncates them and the edge overshoots and oscillates.
- Increase the matrix (smaller pixels), especially in phase
- Apply a reconstruction filter
- Deep-learning reconstruction removes most of it
Higher matrix lowers SNR and may add time. Filters blur fine detail slightly.
This page is one entry from the MRI Technologist Reference
The full reference has 31 protocols, 9 dynamic study timelines, 19 artifacts, 16 scanner problems and 15 safety topics, as a PDF in English and Arabic plus an interactive tool.
Educational reference. It does not replace your site protocols, the radiologist's instructions, the MR safety officer, or the manufacturer's instructions for any implant, device or contrast agent. Parameter values are typical starting points at 1.5 T and must be adapted to the scanner, coil and patient.