Cholesteatoma Localization Using Fused Diffusion-Weighted Images and Thin-Slice T2 Weighted Images

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.

Magnetic Resonance Imaging Artifact Associated With Transcutaneous Bone Conduction Implants: Cholesteatoma and Vestibular Schwannoma Surveillance

OBJECTIVE

To evaluate the magnetic resonance (MR) image artifact and image distortion associated with the two transcutaneous bone conduction implants currently available in the United States.

STUDY DESIGN

Cadaveric study.

METHODS

Two cadaveric head specimens (1 male, 1 female) were unilaterally implanted according to manufacturer guidelines and underwent MR imaging (General Electric and Siemens 1.5 T scanners) under the following device conditions: (1) no device, (2) Cochlear Osia with magnet and headwrap, (3) Cochlear Osia without magnet, and (4) MED-EL Bonebridge with magnet. Maximum metal mitigation techniques were employed in all conditions, and identical sequences were obtained. Blinded image scoring (diagnostic vs nondiagnostic image) was performed by experienced neuroradiologists according to anatomical subsites.

RESULTS

All device conditions produced artifact and image distortion. The Osia with magnet produced diagnostic T1- and T2-weighted images of the ipsilateral temporal bone, however, non-echo planar imaging diffusion-weighted imaging (DWI) was nondiagnostic. The Osia without magnet scanned on the Siemens MR imaging demonstrated the least amount of artifact and was the only condition that allowed for diagnostic imaging of the ipsilateral temporal bone on DWI. The Bonebridge produced a large area of artifact and distortion with the involvement of the ipsilateral and contralateral temporal bones.

CONCLUSION

In summary, of the three device conditions (Osia with magnet, Osia without magnet, and Bonebridge), Osia without magnet offered the least amount of artifact and distortion and was the only condition in which diagnostic DWI was available for the middle ear and mastoid regions on the Siemens MR imaging scanner.

Disease recidivism after subtotal petrosectomy and ear canal closure

PURPOSE

To describe the presentation, diagnosis, and management of chronic otitis media recidivism after subtotal petrosectomy and ear canal closure (STP).

MATERIALS AND METHODS

Patients with temporal bone pathology detected during follow-up after STP were identified in the electronic medical record. Pertinent clinical details regarding surveillance plan, presentation, imaging findings, and revision surgery were collected and analyzed.

RESULTS

A total of 10 patients were identified with recurrent or persistent pathology after STP. The median time to detection was 46 months (IQR 24-84). Five patients (50 %) had non-specific symptomatology, 4 patients (40 %) were completely asymptomatic, and 1 patient (10 %) was asymptomatic outside of two instances of mastoiditis with cochlear implant device infection treated with incision and drainage. One patient (10 %) was noted to have proptosis on examination, but no other patients had objective signs of disease at detection of disease recidivism. Nine (90 %) patients had pathology identified on preoperative imaging. All patients underwent revision surgery, with identification of cholesteatoma in 8 cases (80 %) and cholesterol granuloma in 2 cases (20 %). Extensive disease was noted in 6 patients (60 %), all of whom followed-up greater than 3 years from surgery. All patients tolerated revision surgery without complication.

CONCLUSIONS

Recidivistic disease often remains clinically silent for extended periods of time after STP. Planned follow-up - with imaging or second look surgery - to facilitate early detection should be considered. Undetected disease recurrence or development may result in morbidity in a proportion of patients if surveillance is not performed.

Comparison of the Utility of High-Resolution CT-DWI and T2WI-DWI Fusion Images for the Localization of Cholesteatoma

BACKGROUND AND PURPOSE

Cholesteatoma is an aggressive disease that may lead to hearing impairment. This study aimed to compare the utility of high-resolution CT and TSE-DWI fusion images with that of T2WI and TSE-DWI fusion images in the localization of middle ear cholesteatoma.

MATERIALS AND METHODS

Seventy-one patients with middle ear cholesteatoma were retrospectively recruited. High-resolution CT, T2WI with fat suppression, and TSE-DWI scans were obtained, and image fusion was performed using a 3D reconstruction postprocessing workstation to form CT-DWI and T2WI-DWI fusion images. The quality of the 2 fused images was subjectively evaluated using a 5-point Likert scale with the horizontal semicircular canal transverse position as the reference. Receiver operating characteristic analysis was performed, and the diagnostic efficacies of CT-DWI and T2WI-DWI fusion images in localizing middle ear cholesteatoma were calculated.

RESULTS

The overall quality of T2WI-DWI fusion images was slightly higher than that of CT-DWI fusion images (P < .001), and the semicircular canal was slightly less clear on T2WI-DWI than on CT-DWI (P < .001). No statistical difference was found in the diagnostic confidence between them. In the localization of middle ear cholesteatoma, the accuracy, sensitivity, and specificity of T2WI-DWI fusion images and CT-DWI fusion images were equivalent for involvement of the attic, tympanic cavity, mastoid antrum, and mastoid process, with no statistically significant differences.

CONCLUSIONS

T2WI-DWI fusion images could replace CT-DWI in the preoperative selection of surgical options for middle ear cholesteatoma.

[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.

Comparison of Readout-Segmented Echo-Planar Imaging and Single-Shot TSE DWI for Cholesteatoma Diagnostics

BACKGROUND AND PURPOSE

The high diagnostic value of DWI for cholesteatoma diagnostics is undisputed. This study compares the diagnostic value of readout-segmented echo-planar DWI and single-shot TSE DWI for cholesteatoma diagnostics.

MATERIALS AND METHODS

Thirty patients with newly suspected cholesteatoma were examined with a dedicated protocol, including readout-segmented echo-planar DWI and single-shot TSE DWI at 1.5T. Acquisition parameters of both diffusion-weighted sequences were as follows: b=1000 s/mm,² axial and coronal section orientations, and section thickness of 3 mm. Image quality was evaluated by 2 readers on a 5-point Likert scale with respect to lesion conspicuity, the presence of susceptibility artifacts mimicking cholesteatomas, and overall subjective image quality. Sensitivity and specificity were calculated using histology results as the gold standard.

RESULTS

Twenty-five cases of histologically confirmed cholesteatomas were included in the study group. Lesion conspicuity was higher and fewer artifacts were found when using TSE DWI (both P < .001). The overall subjective image quality, however, was better with readout-segmented DWI. For TSE DWI, the sensitivity for readers 1 and 2 was 92% (95% CI, 74%-99%) and 88% (95% CI, 69%-97%), respectively, while the specificity for both readers was 80% (95% CI, 28%-99%). For readout-segmented DWI, the sensitivity for readers 1 and 2 was 76% (95% CI, 55%-91%) and 68% (95% CI, 46%-85%), while the specificity for both readers was 60% (95% CI, 15%-95%).

CONCLUSIONS

The use of TSE DWI is advisable for cholesteatoma diagnostics and preferable over readout-segmented DWI.