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.