Cerebritis

1-Due to infection of the brain parenchyma by bacterial organisms.

2-They reach the brain via:

-Hematogeneous spread.

-Direct from a septic focus such as in sinus or petrous bone.

-Penetrating wound.

-Congenital heart disease.

3-Cerebritis differs completely from encephalitis as the former can enhance while the latter cannot.

4-In case of cerebritis, you will see patches in the brain parenchyma which will progress to abscess formation after liquefaction.

5-Usually the patient when come to make the brain scan will be the stage of abscess formation.

6-The patches seen in case of cerebritis is similar to that produced by infarction, but we can differentiate by the following:

-In case of infarction, the distribution of the lesion is along territory of a vessel.

-By clinical which is the most important differentials.

7-The presence of air inside the abscess, suggests interference by something like a needle to evacuate or take a specimen from the abscess.

8-Both brain abscess and glioma give appearance of ring enhancement.

In the early stage of brain abscess, it shows regular and thin ring enhancement.

While in case of late stage of the abscess, it will shows regular but thick ring enhancement.

In case of gliomas the ring enhancement of the wall is thick and irregular.

If you cannot judge properly, goes to diffusion sequence where in case of abscess you got diffusion restricted while in tumor you will got diffusion free.

9-Mastoiditis is one of the most common cause of cerebellar abscess.

10-Abscess could forms satellite or daughter abscesses.