A patient undergoes intact canal wall (canal wall up) mastoidectomy with ossiculoplasty for chronic otitis media with cholesteatoma. Six months postoperatively, she presents with recurrent cholesteatoma confirmed on MRI. What is the specific MRI sequence most useful for detecting residual/recurrent cholesteatoma after canal wall up mastoidectomy?
- A T1-weighted with gadolinium contrast
- B Non-echo planar diffusion-weighted imaging (non-EPI DWI) ✓
- C T2-weighted HASTE sequence
- D CISS (Constructive Interference in Steady State) sequence
Correct answer: B. Non-echo planar diffusion-weighted imaging (non-EPI DWI)
Explanation
Non-echo planar diffusion-weighted MRI (non-EPI DWI), such as HASTE-DWI or PROPELLER DWI, is the imaging of choice for detecting residual or recurrent cholesteatoma after canal wall up mastoidectomy. Cholesteatoma contains keratin debris with restricted diffusion, appearing bright on DWI with a low ADC value, distinguishing it from postoperative scar or fluid. Conventional T1 with gadolinium cannot reliably differentiate scar tissue from cholesteatoma. CISS sequences are best for imaging the facial nerve and inner ear structures.
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.