Teenager with fever and mental status changes

CT of intraventricular intracranial abscess — Axial CT with contrast of the brain shows ring enhancing lesions in the anterior horn of the left lateral ventricle and faint enhancement of the ependymal lining of the ventricles. There is hydrocephalus present as well as effacement of the basilar cisterns.

The diagnosis was intraventricular intracranial abscess causing communicating hydrocephalus. When a ventriculostomy catheter was placed, pus shot out of it.