Chronic otitis media (COM) is chronic inflammation of the middle ear mucosa lasting more than 3 months. Two main types exist: simple type (mucosal — no bone erosion, characterized by tympanic membrane perforation) and complicated type (with cholesteatoma — bone erosion present). CT shows soft tissue density opacification in the middle ear cavity and mastoid air cells, mastoid sclerosis (loss of aeration and reactive bone formation due to chronic inflammation). On MRI, granulation tissue and effusion are distinguished by contrast-enhanced sequences; granulation enhances, effusion does not. DWI evaluates for cholesteatoma. Tubotympanic (simple) and atticoantral (complicated) subtypes are determined by clinico-radiologic correlation.
Age Range
5-70
Peak Age
30
Gender
Equal
Prevalence
Very Common
Chronic otitis media develops as a result of recurrent acute otitis episodes or persistent Eustachian tube dysfunction. Eustachian tube obstruction creates negative pressure in the middle ear, leading to mucosal inflammation and secretory changes. Chronic inflammation causes loss of aeration in mastoid cells and formation of sclerotic bone — since this is osteoblastic reactive bone accumulation rather than osteoclastic resorption, a dense sclerotic appearance forms on CT. Granulation tissue (neovascularization + fibroblast proliferation + chronic inflammatory cells) has a rich vascular network and shows avid enhancement with gadolinium-based contrast — this property differentiates it from avascular effusion. Tympanic membrane perforation forms due to chronic pressure and necrosis. Cholesteatoma development begins with retraction pocket formation or epithelial migration from the perforation margin and is a separate complication leading to bone erosion.
Complete loss of aeration with opacification and reactive bone sclerosis of normally pneumatized mastoid cells is the CT signature of chronic otitis media. This finding is critical in differentiation from acute otitis media — in acute otitis the mastoid is still partially pneumatized, while in chronic otitis it becomes completely sclerotic.
On HRCT, soft tissue density opacification (30-60 HU) is seen in the middle ear cavity and mastoid air cells. Normally pneumatized mastoid cells are opacified and sclerotic — this is the result of chronic inflammation. Opacification may represent effusion, mucosal thickening, and/or granulation tissue; CT cannot reliably differentiate these three (contrast MRI required). If bone structures are intact, simple COM is diagnosed.
Report Sentence
Diffuse opacification and sclerotic appearance of the right/left mastoid air cells is seen, findings consistent with chronic otitis media.
On contrast-enhanced T1-weighted sequences, granulation tissue shows avid enhancement (due to rich vascular network), while effusion does not enhance. This distinction is critical for treatment planning: granulation tissue may respond to antibiotic therapy, effusion may require ventilation tube. Mucosal thickening may also enhance. If DWI is negative, cholesteatoma is excluded.
Report Sentence
On contrast-enhanced sequences, part of the middle ear opacification shows enhancement (granulation tissue), while the non-enhancing component is consistent with effusion.
In simple type chronic otitis media, the ossicular chain is intact — this is the most important differentiation from the cholesteatoma-associated type. Malleus, incus, and stapes are seen in normal position and morphology. However, effusion/granulation tissue surrounding the ossicles may contribute to conductive hearing loss (ossicular fixation). Intact bone structures provide important information for surgical planning.
Report Sentence
The ossicular chain is intact with no bone erosion attributable to cholesteatoma.
On DWI MRI, effusion and granulation tissue of chronic otitis media do not show diffusion restriction. This finding excludes cholesteatoma and changes treatment planning. If DWI is negative, medical treatment can be prioritized; if DWI is positive, cholesteatoma should be considered and surgery planned.
Report Sentence
No diffusion restriction is seen in the middle ear opacification on DWI, with no findings suggestive of cholesteatoma.
Although HRCT cannot directly demonstrate tympanic membrane perforation, indirect signs exist: soft tissue/fluid in the external auditory canal (drainage through perforation), continuity of air-fluid level between middle ear and EAC, disruption of normal relationship between malleus handle and tympanic membrane. Evaluated in coronal and axial planes.
Report Sentence
Soft tissue/fluid is seen in the external auditory canal, an indirect finding consistent with tympanic membrane perforation; clinical correlation is recommended.
Criteria
Chronic mucosal inflammation, tympanic membrane perforation (anterior-inferior), no bone erosion, no cholesteatoma.
Distinct Features
May respond to medical treatment, repair possible with tympanoplasty, good prognosis.
Criteria
Cholesteatoma-associated, bone erosion present, posterior-superior perforation or attic retraction.
Distinct Features
Surgical treatment mandatory (tympanomastoidectomy), cholesteatoma confirmed by DWI MRI, high complication risk.
Criteria
Calcification/hyalinization of tympanic membrane and/or mucosa due to chronic inflammation.
Distinct Features
Calcific plaques in middle ear structures on CT (>200 HU), ossicular fixation, conductive hearing loss.
Distinguishing Feature
Cholesteatoma shows bright DWI + bone erosion + no enhancement; simple COM is DWI negative + bone intact + granulation enhances
Distinguishing Feature
Glomus tympanicum is focal hypervascular mass on promontory; COM shows diffuse opacification without focal promontory mass
Distinguishing Feature
Otosclerosis shows focal lucency in otic capsule without middle ear opacification; COM shows diffuse opacification with intact otic capsule
Urgency
routineManagement
medicalBiopsy
Not NeededFollow-up
6-monthSimple type COM can be managed with medical treatment (antibiotics, ear aspiration); if non-responsive, tympanoplasty is considered. Cholesteatoma-associated type requires surgery. CT is used for bone detail, MRI for cholesteatoma exclusion and granulation-effusion differentiation. Complications (mastoiditis, sigmoid sinus thrombosis, intracranial abscess) require urgent intervention.
Chronic otitis media is one of the most common causes of conductive hearing loss. Simple type may respond to medical treatment; however, surgery is mandatory if cholesteatoma is present. Complications include mastoiditis, petrositis, facial nerve paralysis, and intracranial infection.