Non-EPI DW MRI in planning the surgical approach to primary and recurrent cholesteatoma

OBJECTIVE: To investigate a correlation between preoperative non-echo planar diffusion-weighted magnetic resonance imaging (non-EPI DW MRI) with surgical findings of localization and extension of cholesteatoma and to develop criteria for surgical planning. PATIENTS: Preoperative non-EPI DWMRI was available and positive for cholesteatoma in 27 patients with primary and 23 with residual/recurrent lesions. INTERVENTIONS: Patients with cholesteatoma limited to the middle ear and its extensions were managed with a transcanal endoscopic approach. Patients with extension of the cholesteatoma posteriorly to the lateral semicircular canal underwent retroauricular mastoidectomy combined with an endoscopic approach. MAIN OUTCOME MEASURE: Comparison of preoperative radiologic to surgical findings. RESULTS: DWI showed isolated tympanic and attic extension in 33 cases and attico-antral and mastoid extension in 17 cases. MRI findings correlated with surgical findings in all patients with primary cholesteatoma, 19 of whom were managed with a transcanal endoscopic approach and 8 with endoscope-assisted ear surgery. The transcanal endoscopic approach was applied in 14 of the patients with residual/recurrent cholesteatoma, and the other 9 residual/recurrent lesions were eradicated using endoscope-assisted mastoidectomy. DWI overestimated cholesteatoma sites in 1 patient with residual lesion. The smallest cholesteatoma detected on DWI was a 3-mm lesion in the middle ear over the facial nerve. CONCLUSION: Primary and residual/recurrent cholesteatoma was accurately detected on non-EPI DWI with 98% clinical and radiologic concordance. Lesions less than 8 mm confined to the middle ear and its extensions can be eradicated with a minimally invasive endoscopic transcanal technique, whereas endoscope-assisted retroauricular mastoidectomy is preferred for larger lesions.