In a patient with cholesteatoma, CT temporal bone (non-contrast) with reformats is the investigation of choice over MRI for initial evaluation. However, MRI DWI (diffusion-weighted imaging) is increasingly used because it:

• A Shows cholesteatoma as a hypointense lesion on T1 with ring enhancement
• B Detects residual or recurrent cholesteatoma as a restricted diffusion (bright DWI) lesion non-invasively, replacing second-look surgery in some centres ✓
• C Accurately measures ossicular chain continuity better than CT
• D Is the only modality that demonstrates the extent of bone erosion in cholesteatoma

Explanation

Non-echo-planar diffusion-weighted MRI (non-EP DWI) shows cholesteatoma as bright (restricted diffusion) due to its keratin debris content, while middle ear fluid does not restrict. This allows non-invasive detection of residual or recurrent disease after tympanomastoid surgery, potentially replacing second-look exploration. CT remains superior for demonstrating bony erosion, ossicular destruction and anatomical detail preoperatively. DWI does not assess ossicular chain integrity or bone erosion.

Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.