Presentation
Headache.
Patient Data
A dilated cystic space is seen in the midline below the posterior body of the corpus callosum displacing the fornices upwards and the internal cerebral veins downwards. The pineal gland can be seen as separated from this region below the internal cerebral veins. It follows the CSF signal in all pulse sequences.
Incidental left frontal periventricular white matter non-specific small foci of high signal in FLAIR. Incidental paranasal sinusitis.
Case Discussion
A cavum velum interpositum is an anatomical variant in which the regular cistern of the velum interpositum is enlarged. The term cavum velum interpositum cyst should be used when the axial transverse measurement is greater than 1 cm, the edges are outwards bowed, and there is a positive mass effect.