Pulsation and flow ghosts in MRI: cause and fixes
Copies of a vessel or of CSF appear at regular intervals along the phase direction and can look like lesions. This is how to recognise them and move or remove them.
Pulsation / flow ghosts
Evenly spaced bright or dark copies of a vessel or of CSF along the phase direction; may mimic a lesion in the liver, spine or brainstem.
Pulsatile flow changes signal and phase from one TR to the next. Ghost spacing depends on TR, heart rate and the number of phase lines.
- Flow compensation (gradient moment nulling)
- Saturation band upstream of the vessel
- Swap phase so ghosts miss the area of interest
- Cardiac or peripheral gating
- Check the suspected lesion in a second plane or with swapped phase: a ghost moves, a lesion does not
Flow compensation lengthens minimum TE. Saturation bands add SAR and reduce slices per TR. Gating ties TR to the heart rate.
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.