Presentation
Headache ?cause. Incidental finding.
Patient Data
Note: This case has been tagged as "legacy" as it no longer meets image preparation and/or other case publication guidelines.

Single FLAIR axial image through the frontal horns of the lateral ventricles demonstrates small triangular regions of high signal abutting the anterolateral aspect of the ventricles. This is a normal finding which is called ependymitis granularis.
Case Discussion
What?
Ependymitis granularis is characterized by symmetrical foci of periventricular T2 and FLAIR hyperintensity anterior and lateral to the frontal horns of the lateral ventricles.
The foci are usually small - less than 1 cm - and have a triangular morphology extending laterally from the callosal genu.
Why?
It is thought to occur secondary to a focal breakdown of the ependymal lining with adjacent astrocytic gliosis; and into this region periependymal CSF/fluid preferentially drains.
Is it important?
Well no. Despite its name giving the sound of something that is inflammatory, and a 1926 article that claimed it as a cause of chronic internal hydrocephalus, it is now thought to be an anatomical variant of no clinical consequence 1,2.