Three years after canal wall up surgery for cholesteatoma, a patient needs evaluation for residual disease. Which imaging modality provides the highest specificity for detecting small residual cholesteatoma and can replace routine second-look surgery?

• A High-resolution CT of the temporal bone with bone algorithm
• B Non-echo-planar diffusion-weighted MRI ✓
• C Contrast-enhanced T1 weighted MRI
• D PET-CT with fluorodeoxyglucose tracer

Explanation

Cholesteatoma keratin restricts water diffusion, appearing bright on high b-value diffusion weighted sequences. Non-echo-planar (HASTE-type) DWI avoids susceptibility artefact at the skull base and detects lesions as small as 2 to 3 mm with specificity above 90 percent. HRCT cannot distinguish cholesteatoma from fluid or granulation tissue, and conventional T1 MRI lacks this restriction characteristic.

Reference: Scott-Brown's Essential Otorhinolaryngology, 3rd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.