Learning Objectives: To demonstrate that CMFI is a reliable diagnostic modality for not only preoperatively identifying cholesteatomas but also postoperatively identifying early-stage residual cholesteatomas.
Introduction: Residual cholesteatomas have been difficult to accurately detect at an early stage during follow-up examinations of patients whom had previously undergone surgery for removal of a primary cholesteatoma. Typically shadows will appear on a CT scan, but cannot be confirmed as a residual cholesteatoma until a second CT scan is taken several months later. This second CT is then compared to the first CT scan to determine whether the shadow has increased in size, thus strongly suggesting the presence of a cholesteatoma. However, color mapped fusion imaging (CMFI) can be used to immediately evaluate such shadows. If a shadow shows up as a red area, the shadow is likely to be a residual cholesteatoma and can be immediately removed. Thus CMFI is useful in the postoperative follow-up evaluations of patients for residual cholesteatomas.
Patients and Methods: Ninety patients who had undergone the removal of a primary acquired middle ear cholesteatoma and were undergoing postoperative follow-up evaluations for residual cholesteatomas at 6-month intervals. Each patient initially underwent a CT scan. If a shadow was found which suggested the presence of a residual cholesteatoma, a CMFI was taken to determine whether the shadow was actually a cholesteatoma. This CMFI is created by combining a 1-mm thin slice non-EPI DWI with MR cisternography (MRC).
Results: Shadows were found on the initial CT scan in 68/90 patients. The presence of a residual cholesteatoma was strongly suggested in 5/68 patients based on the CMFI. These 5 patients all underwent surgery for cholesteatoma removal. The CMFI evaluations for these patients were compared to the intraoperative findings. All 5 patients were found to have a residual cholesteatoma in the same anatomical location as indicated by the CMFI and these cholesteatomas were all successfully removed.
Conclusion: CMFI is a reliable diagnostic modality for postoperatively identifying early-stage residual cholesteatomas.
