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

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.

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.

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.

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.

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).