Non-echo planar diffusion-weighted MRI increases follow-up accuracy after one-step step canal wall-down obliteration surgery for cholesteatoma

Abstract

CONCLUSION: Non-echo planar (non-EPI) diffusion-weighted (DW) magnetic resonance imaging (MRI) increases the number of detected cholesteatoma after one-step canal wall-down (CWD) obliteration surgery for cholesteatoma compared with clinical evaluation alone. OBJECTIVE: To evaluate the use of DW-MRI for detection of cholesteatoma after surgical treatment using a CWD obliteration technique. METHODS: Thirty-eight adult patients (41 ears) treated with an identical one-step CWD obliteration surgical technique were included in a prospective and blinded study. All patients were investigated with non-EPI and EPI DW-MRI 1-9 months after the clinical examination. Follow-up time after primary surgery varied between 10 and 234 months. DW-MRI was assessed by two neuroradiologists and compared with clinical results. Inter-rater agreement was calculated. Positive non-EPI DW-MRI cases underwent revision surgery within 18-159 days after imaging. RESULTS: Seven of 41 cases were evaluated as positive for cholesteatoma on non-EPI DW-MRI. Since one patient refused surgery six of these seven cases underwent surgical revision and all were verified. There was agreement between clinical and non-EPI findings in five of eight cases. EPI findings correlated poorly with non-EPI and clinical findings. Inter-rater agreement (Cohen's kappa) was 0.91 for non-EPI DW-MRI (p < 0.001) and -0.062 for EPI DW-MRI (p = 0.43).