Limitations of non-echo planar diffusion weighted magnetic resonance imaging (non-EPI MRI) in cholesteatoma surveillance after ossicular chain reconstruction. A prospective study.

OBJECTIVE

Non-echo planar diffusion weighted magnetic resonance imaging is a reliable surveillance tool of residual cholesteatoma nowadays. It is not known whether the material of the ossicular chain prosthesis modifies the sensitivity and specificity of MRI in these cases. The aim of the study was to compare the sensitivity, specificity and a localization-specific accuracy of non-EPI DW MRI sequences for residual cholesteatoma in the following 3 subgroups: patients with titanium ossicular prosthesis (group T), with autologous cortical bone columella (group A) or without any reconstruction (group WR) of hearing bones.

METHODS

This prospective study covered 28 cases with cholesteatoma of the middle ear undergone second-look surgery, who had preoperative PROPELLER DW-MRI. Surgical findings were compared to the results of the DWI-MRI.

RESULTS

The overall sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were: 0.76-0.8-0.76-0.8. Group T, group A and group WR sensitivity was 0.83-0.6-1, specificity: 0.75-0.75-0.85, PPV: 0.83-0.75-0.66, NPV: 0.75-0.6-1. Overall accuracy was 0.78. Size of missed cholesteatoma was 2-4 mm (mean: 2.66±1.15).

CONCLUSIONS

Various materials are suitable for ossicular chain reconstruction. The poor detectability of residual or recurrent cholesteatoma in the middle ears reconstructed with autologous bony prosthesis may still claim second-look surgery instead of the usage of non- EPI DWI sequences independently in these patients.