The value of non-echo planar HASTE diffusion-weighted MR imaging in the detection, localisation and prediction of extent of postoperative cholesteatoma

MRI for the diagnosis of recurrent middle ear cholesteatoma in children--can we optimize the technique? Preliminary study

BACKGROUND

Recurrent cholesteatoma after surgical excision occurs frequently in children. Until recently, a surgical second look was mandatory and considered as standard reference. MRI including a delayed T1 sequence after gadolinium injection and diffusion-weighted imaging (DWI) has proved its efficiency but has been evaluated mainly in adults.

OBJECTIVE

Our purpose was to evaluate the accuracy of DWI to diagnose recurrence of cholesteatoma in children.

MATERIALS AND METHODS

We evaluated prospectively with MRI 20 ears in 18 children who had had surgery for cholesteatoma. We compared DWI and delayed T1-weighted images following gadolinium administration with intraoperative or follow-up findings. We calculated the sensitivity and specificity of each sequence for the diagnosis of recurrent cholesteatoma.

RESULTS

Sensitivity to diagnose recurrent cholesteatoma was 87% for both DWI and delayed post-gadolinium sequences, specificity was 71% and 83%, respectively. Adding both sequences, the sensitivity was 87%, the specificity 100%. There was one false negative probably due to small size recurrence.

CONCLUSION

In our series, DWI was reliable to diagnose recurrent cholesteatoma in children and allows avoiding surgery when negative. However, because small recurrences less than 5 mm may be missed, follow-up must be prolonged (5 years).

[The use of MRI DWI-imaging in assessment of cholesteatoma recurrences after canal wall up technique]

INTRODUCTION

The use of closed technique in cholesteatoma treatment carries a significant risk of development of residual disease thus requires a second look operation in a proportion of patients. In those with no residual cholesteatoma the second surgery could be avoided.

THE AIM OF THE STUDY

was to evaluate the use of non-echo planar HASTE diffusion-weighted MR imaging in the detection of cholesteatoma in patients after canal wall up surgery due to cholesteatoma.

MATERIAL AND METHODS

We evaluate the results of half-Fourier-acquisition single-shot turbo-spin-echo (HASTE) diffusion-weighted magnetic resonance imaging in 18 patients after canal wall up surgery performed 6 to 20 months after primary surgery. 16 patients were operated in our center and 2 elsewhere. All the patients underwent second look surgery that verified the result of MRI scanning.

RESULTS

MRI DWI detected 2 cholesteatomas in patients operated elsewhere and none in patients operated in our center. Four cholesteatomas were found during second look operations. Two false negatives were in 1 patient with cholesteatoma pearl of less than 2mm in diameter and in 1 patient with mural cholesteatoma. There were no false positive results.

CONCLUSION

Non EPI MRI DWI can be used as a screening tool to detect residual or recurrent cholesteatoma and may substitute the need of second look surgery.