Surgical mapping of middle ear cholesteatoma with fusion of computed tomography and diffusion-weighted magnetic resonance images: Diagnostic performance and interobserver agreement

Fusion computed tomography-magnetic resonance imaging scans for pre-operative staging of congenital middle-ear cholesteatoma

OBJECTIVE

To evaluate if fusion computed tomography-diffusion-weighted magnetic resonance imaging may have a role in the pre-operative assessment of congenital middle-ear cholesteatoma.

METHODS

A retrospective chart review of surgically treated congenital middle-ear cholesteatoma patients over a 2-year timespan was conducted. Pre-operative staging was performed on computed tomography and fusion computed tomography-diffusion-weighted magnetic resonance imaging based on extension of the disease according to the ChOLE classification system and the Potsic classification system. Intra-operative staging was compared to imaging findings to evaluate accuracy of the two imaging modalities in predicting congenital middle-ear cholesteatoma extent.

RESULTS

Computed tomography was able to correctly predict congenital middle-ear cholesteatoma extent in three out of six cases according to the ChOLE classification system, all of which were staged as Ch1a and Ch1b on pre-operative computed tomography. Cases in which computed tomography was not able correctly to determine congenital middle-ear cholesteatoma extent were staged as Ch3 on pre-operative computed tomography. Fusion scans correctly determined congenital middle-ear cholesteatoma extent in all cases according to the ChOLE classification.

CONCLUSIONS

Fusion computed tomography-diffusion-weighted magnetic resonance imaging may be helpful in cases of congenital middle-ear cholesteatoma where pre-operative computed tomography shows mastoid and antrum opacification, in which computed tomography alone may overestimate cholesteatoma extension beyond the level of the lateral semi-circular canal.

Selection of a Surgical Approach for Middle Ear Cholesteatoma Based on the Fusion Images of Non-Echo Planar Diffusion-Weighted MRI and CT

PURPOSE

This study aimed to explore the ability of fusion images of non-echo planar diffusion-weighted magnetic resonance imaging (non-EPI-DWI MRI) and computed tomography (CT) to accurately locate cholesteatoma and plan the surgical approach.

METHODS

In the first part, 41 patients were included. Their CT images and non-EPI DWMRI images were fused. The scope of cholesteatoma in the fusion image was compared with that in the surgical video to evaluate the capability to locate cholesteatoma. A total of 229 patients were included in the second part, and they were divided into 2 groups. We chose the surgical approach for the CT group and the fusion group, and compared the accuracy of surgical approaches in the CT group and the fusion group using the surgical records.

RESULTS

The location of cholesteatoma shown in the fusion images was almost identical to that observed during the operation (kappa = .862). The overall specificity and sensitivity of the fusion images in locating cholesteatoma were 94.12% and 93.06%, respectively. The accuracy of surgical approach selection based on the fusion images (99.02%) was higher than that of surgical approach selection based on the CT images (85.83%).

CONCLUSION

It is recommended that the fusion images be used to locate the range of the cholesteatoma before operation.

Accuracy of High-Resolution Computed Tomography Compared to High-Definition Ear Endoscopy to Assess Cholesteatoma Extension

OBJECTIVE

To correlate radiographic evidence of cholesteatoma in the retrotympanum with intraoperative endoscopic findings in cholesteatoma patients and to evaluate the clinical relevance of radiographic evidence of cholesteatoma in the retrotympanum.

STUDY DESIGN

Case series with chart review.

SETTING

Tertiary referral center.

METHODS

Seventy-six consecutive cases undergoing surgical cholesteatoma removal with preoperative high-resolution computed tomography (HRCT) were enrolled in this study. A retrospective analysis of the medical records was conducted. The extension of cholesteatoma regarding different middle ear subspaces, into the antrum and mastoid were reviewed radiologically in preoperative HRCT and endoscopically from surgical videos. Additionally, facial nerve canal dehiscence, infiltration of the middle cranial fossa, and inner ear involvement were documented.

RESULTS

Comparison of radiological and endoscopic cholesteatoma extension revealed statistically highly significant overestimation of radiological cholesteatoma extension for all retrotympanic regions (sinus tympani 61.8% vs 19.7%, facial recess 69.7% vs 43.4%, subtympanic sinus 59.2% vs 7.9%, and posterior sinus 72.4% vs 4.0%) and statistically significant overestimation for mesotympanum (82.9% vs 56.6%), hypotympanum (39.5% vs 9.2%), and protympanum (23.7% vs 6.6%). No statistically significant differences were found for epitympanum (98.7% vs 90.8%), antrum (64.5% vs 52.6%), and mastoid (26.3% vs 32.9%). Statistically significant radiological overestimation of facial nerve canal dehiscence (54.0% vs 25.0%) and invasion of tegmen tympani (39.5% vs 19.7%) is reported.

CONCLUSION

Radiologic cholesteatoma extension in different middle ear subspaces is overestimated compared to the intraoperative extension. The preoperative relevance of radiological retrotympanic extension might be limited in the choice of approach and transcanal endoscopic approach is always recommended first.

The Role of Fusion Technique of Computed Tomography and Non-echo-planar Diffusion-weighted Imaging in the Evaluation of Surgical Localization of Cholesteatoma

Objective:

In recent years, the fusion of computed tomography (CT) and non-echo-planar diffusion-weighted magnetic resonance imaging (non- EPI DWI) has been preferred in cholesteatoma localizations. This study aimed to investigate the role of CT and non-EPI DWI fusion imaging in cholesteatoma localizations.

Methods:

This retrospective study included 39 patients who underwent chronic otitis media operation [mean age of 35.10±15.33 years (18-67 years), 64.1% female, and 35.9% male] and had preoperative high-resolution temporal bone CT and non-EPI DWI examinations. Images were sent to the Advantage Workstation VolumeShare 7 for fusion. These selected images were fused on the workstation and were manually corrected by the radiologist. The sensitivity, specificity, positive and negative predictive values, and diagnostic accuracies of fused images of CT and non-EPI DWI were evaluated according to anatomic cholesteatoma localizations based on surgical data.

Results:

The sensitivity, specificity, positive and negative predictive values, and diagnostic accuracies of non-EPI DWI for detecting cholesteatomas were 97.14%, 75.00%, 97.14%, 75.00%, and 94.87%, respectively. Three true-negative, one false-positive, and one false-negative case were observed according to surgical results in detecting the presence of a cholesteatoma with non-EPI DWI. Moderate agreement was determined between the surgical and radiological results in detecting the presence of a cholesteatoma (k=0.721). Detecting the lesion of localization on the fused images compared to surgical found an almost perfect agreement in the mastoid antrum (k=0.948), strong agreement in the hypotympanum and mastoid cells (k=0.894), moderate agreement in the epitympanum (k=0.653), and weak agreement in those in the mesotympanum (k=0.540).

Conclusions:

The surgeons’ determinations are supported by the guidance of temporal CT and non-EPI DWI fused images. Therefore, preferring the fusion imaging technique could increase the quality of life by reducing unnecessary operations.

[Combination of CT and MRT in the diagnostic of middle ear cholesteatoma. Fusion technology is precise localization tool]

Computed tomography (CT) and magnetic resonance imaging (MRI) methods of the middle ear cholesteatoma diagnostic have its advantages and disadvantages. Fusion technology is a post-processing process of CT and MRI images. Its main advantage is the localization of MR-hyperintensive cholesteatoma within the bony anatomical structures obtained on CT, which provides the surgeon with important information both before planning the primary surgical intervention and during a second revision for recurrent cholesteatoma.

Novel Radiologic Approaches for Cholesteatoma Detection: Implications for Endoscopic Ear Surgery

Technological advancement in computed tomography (CT) and MRI has improved cholesteatoma detection rates considerably in the past decade. Accurately predicting disease location and extension is essential for staging, planning, and preoperative counseling, in particular in the newer approach of endoscopic ear surgery. Improved sensitivity and specificity of these radiological methods may allow the surgeon to confidently monitor patients, therefore avoiding unnecessary surgery. This article outlines recent advances in CT and MRI technology and advantages and disadvantages of the newer techniques. Emphasis on improving the feedback loop between the radiologist and surgeon will increase the accuracy of these new technologies.