ependymitis granularis

Ependymitis granularis sounds far more worrying than it actually is. The term refers to symmetrical foci of periventricular high T2 and FLAIR signal hyperintensity anterior and lateral to the frontal horns. It is just an anatomical variant, usually small, less than 1 cm, and has a triangular morphology extending laterally from the callosal genu. Pathologic lesions tend to be larger and demonstrate corresponding low signal intensity in T1WI.

Pathology

Three findings contribute to the appearance :

  • decreased myelin 
  • focal breakdown of the ependymal lining and astrocytic gliosis (true ependymitis granularis)
  • increased periependymal and extracellular fluid
  • Despite the name, which suggests an inflammatory cause, and a 1926 article that claimed it as a cause of chronic internal hydrocephalus, it is just an anatomical variant.

    Differential diagnosis

    Siehe auch: