The diagnosis of brain abscesses is established by a computed tomography (CT) scan with contrast.

CT scans can be used to evaluate all cranial structures including the paranasal sinuses, mastoids, and the middle ear.^[1] They can detect edema, hydrocephalus, shifts, or ventricular ruptures. At the initial phase of the inflammation (referred to as cerebritis), the immature lesion does not have a capsule and it may be difficult to distinguish it from other space-occupying lesions or infarcts of the brain. Within 4-5 days, the inflammation and the concomitant dead brain tissue are surrounded with a capsule, which gives the lesion the famous ring-enhancing appearance on CT examination with contrast (since intravenously applied contrast material can not pass through the capsule, it is collected around the lesion and looks as a ring surrounding the relatively dark lesion).

Lumbar puncture procedure, which is performed in many infectious disorders of the central nervous system, is contraindicated in this condition because removing a certain portion of the cerebrospinal fluid (CSF) may alter the concrete intracranial pressure balances and cause a part of the brain tissue to move out of the skull (brain herniation).^[2]