Susceptibility artefact on brain MRI due to gas bubbles
Post-operative examination immediately following excision of posterior fossa mass
Loading Stack -
0 images remaining
Multiple low signal intensity rounded filling defects with in the subarachnoid space and lateral ventricles anteriorly. These are poorly seen on the FLAIR sequence, better seen on T2-weighting and "bloom" on the SWI sequence.
It is important to recognize artefacts on MRI in order to avoid error in reporting. The clinical history in this case is important as well as the distribution of the signal alteration (floating anteriorly with the patient in a supine position).