Recidivous cholesteatoma: DWI MR after canal wall up and canal wall down mastoidectomy.

OBJECTIVES: To investigate the correlation between preoperative non-echo planar diffusion-weighted (non-EPI DWI) MR imaging with surgical findings of recidivous middle ear cholesteatoma after canal wall up (CWU) and canal wall down (CWD) mastoidectomy.

BACKGROUND: The detection of recidive cholesteatoma after CWU and after CWD procedures, when the trepanation cavity is spontaneously closed by soft tissue, is possible by second-look and revision surgery. However, many cases prove to be negative of the disease. To avoid unnecessary operational risks we adopted a novel imaging method to evaluate its potential in the detection of recidivous cholesteatoma.

MATERIAL AND METHODS: The prospective study included 27 cases. Fifteen cases were revised after CWD and 12 cases were second-look surgeries after CWU procedures. All patients underwent the MR protocol: T2-weighted, T1-weighted and non-EPI DWI. The finding on MR correlated with peroperative presence of cholesteatoma.

RESULTS: Non-EPI DWI sequence showed an increased signal intensity in 16/27 (59 %) cases. This correlated with surgical findings in all 7 patients after CWU and in 8 patients after CWD. The overall sensitivity, specificity, positive and negative predictive values of non-EPI DWI were 83.3 %, 88.8 %, 93.8 % and 72.7 %, respectively. DWI presented a sensitivity of 100 % and specificity of 85.7 % in the subgroup of patients after CWD mastoidectomy.

CONCLUSION: Residual and/or recurrent cholesteatoma can be accurately detected by DWI MR. It can be used as a screening method to select patients, who are indicated to second-look or revision surgery after CWU and CWD mastoidectomy (Tab. 1, Fig. 3, Ref. 49).