CT imaging is essential in establishing a diagnosis of malignant necrotizing otitis externa by revealing the extent of infection past the ear canal and extension to adjacent tissues.

CT scan of the head is essential in diagnosing malignant necrotizing otitis externa by revealing the extent of infection into the temporal or intracranial soft tissue.^[1] CT scan of the head in cases of malignant otitis externa may reveal:^{_Radiology_Reference_Article_|_Radiopaedia.org-2|[2]}

• Thickening and enhancing soft tissue in the region of the external auditory canal with or without formation of a phlegmon or abscess
  • In the case of an abscess, cartilaginous border enhancing collection(s) with a low attenuation (necrotic) center may be observed.
• The route of infection:
  • Anteroinferiorly to involve the suprahyoid neck spaces
  • Direct intracranial spread by erosion of the cartilaginous-bone in the external auditory canal
• Destruction of temporal bones and opacified mastoid air cells
• Destruction of the cortex of the mastoid^[3]
• Underlying ause of facial palsy by localization of inflammation relative to the cranial nerves