Inflow and CSF flow effects in MRI
Bright vessels on the first slices and dark or bright CSF that looks like a lesion. Flow explains both.
Inflow and CSF flow effects
Bright vessels in the first or last slices of a stack; bright CSF in the basal cisterns, foramen of Monro or posterior fossa on FLAIR; dark flow voids in CSF on T2 of the spine.
Fresh, unsaturated spins enter the slice with full magnetization. In FLAIR, CSF flowing in from outside the inversion slab was not inverted, so it is not nulled.
- Saturation bands above and below the stack
- Flow compensation
- 3D FLAIR (non-selective inversion)
- Check the finding in another plane before calling it subarachnoid disease
The same effect is the basis of TOF angiography.
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.