Cyst with dot sign (neurocysticercosis)

The cyst with dot sign is seen in neurocysticercosis and represents the parasitic cyst with, usually eccentric, scolex.

It can be seen on both MRI and CT at:

  • the vesicular stage (CSF density / intensity cyst - denser / hyperintense scolex) and
  • colloidal vesicular stage (enhancement of wall and scolex)

It should not be confused with the dot that can be seen in a Rathke cleft cyst.