Gamuts
Subdural empyema
May Cause
Avascular intracranial mass
Avascular zone near the brain surface
Extra-axial lesion
Hypodense supratentorial lesion
Linear meningeal enhancement
Ring-enhancing intracranial lesion
May Be Caused by
Common
Ethmoid sinusitis
Frontal sinusitis
Penetrating trauma
Uncommon
Craniectomy
Mastoiditis
Meningitis
Middle ear infection
Osteomyelitis
Surgery