Imaging of temporal bone inflammations in children: a pictorial review

Purpose: Understanding the underlying pathophysiology and the patterns of disease spread is crucial in accurate image interpretation. In this pictorial review, the common and important inflammatory processes of the temporal bone in children will be discussed, and key computed tomography (CT) and magnetic resonance imaging (MRI) features described. Methods: Inflammatory processes are categorized by anatomical location: the petrous apex and the inner, middle and outer ear. A complete review of the literature is provided. Results: Cholesteatoma, cholesterol granuloma and mucoceles are inflammatory processes that occur across the anatomical subsites of the temporal bone, whilst site-specific inflammatory processes include labyrinthitis ossificans in the inner ear and keratosis obturans in the external ear. Infection is a key cause of inflammation in the temporal bone, and specific infections include petrous apicitis, otitis media and necrotizing otitis externa. Finally, important mimics and do-not-touch lesions are considered. CT and MRI are complementary in assessing these disorders, as two of the most important diagnostic clues are the presence of bone erosion, best appreciated on CT, and true diffusion restriction as seen on MRI. Flow charts to assist in the diagnosis of paediatric temporal bone inflammatory disease are also provided. Conclusion: Paediatric temporal bone inflammatory processes are common and can have severe clinical sequelae. Timely intervention, facilitated by correct radiological diagnosis, can often prevent progression of disease, loss of hearing and systemic illness