Application of Multiplanar Volume Reconstruction Technique for the Assessment of Electrode Location and Analysis of the Correlation to Cochlear Programming and Performance in Common Cavity Deformity

Purpose: Owing to the characteristic anatomy, cochlear implantation (CI) for common cavity deformity (CCD) has resulted in varied outcomes and frequent facial and vestibular nerve stimulation. The current study analyzed the correlation among the distance between each electrode and cavity wall (abbreviation, D), programming parameters, and performances outcomes.Materials and Methods: The current, retrospective study included 25 patients (27 ears) with CCD underwent CI. The multiplanar volume reconstruction (MPVR) techniques were employed to reconstruct and evaluate the postoperative temporal bone CT. The D and maximum comfortable level (MCL) 6 months after CI, facial and vestibular nerve stimulation, and outcomes 1, 2, and 3 years after CI pertaining to the questionnaires were documented and analyzed.Results: The patients were divided into symptomatic (10, 37%) and asymptomatic (17, 63%) groups according to with or without facial and vestibular nerve stimulation. The MCL pertaining to the symptomatic group was significantly lower than asymptomatic group, but Categories of Auditory Performance (CAP) scores 1 year after surgery was better (p < 0.05). The subjects were divided into flat (12, 44.4%) and curved (15, 55.6%) groups based on the contour of MCL map. The MCL and D were lower and shorter in the curved group than the flat group, and CAP score 1 year after surgery and Speech Intelligibility Rating (SIR) 3 years after surgery were better (p < 0.05).Conclusion: Although abnormal reactions such as facial and vestibular nerve stimulation were observed to be more frequent, lower MCL and better outcomes were observed in relation to the shorter D.

Fully automated segmentation in temporal bone CT with neural network: a preliminary assessment study

Background Segmentation of important structures in temporal bone CT is the basis of image-guided otologic surgery. Manual segmentation of temporal bone CT is time- consuming and laborious. We assessed the feasibility and generalization ability of a proposed deep learning model for automated segmentation of critical structures in temporal bone CT scans. Methods Thirty-nine temporal bone CT volumes including 58 ears were divided into normal (n = 20) and abnormal groups (n = 38). Ossicular chain disruption (n = 10), facial nerve covering vestibular window (n = 10), and Mondini dysplasia (n = 18) were included in abnormal group. All facial nerves, auditory ossicles, and labyrinths of the normal group were manually segmented. For the abnormal group, aberrant structures were manually segmented. Temporal bone CT data were imported into the network in unmarked form. The Dice coefficient (DC) and average symmetric surface distance (ASSD) were used to evaluate the accuracy of automatic segmentation. Results In the normal group, the mean values of DC and ASSD were respectively 0.703, and 0.250 mm for the facial nerve; 0.910, and 0.081 mm for the labyrinth; and 0.855, and 0.107 mm for the ossicles. In the abnormal group, the mean values of DC and ASSD were respectively 0.506, and 1.049 mm for the malformed facial nerve; 0.775, and 0.298 mm for the deformed labyrinth; and 0.698, and 1.385 mm for the aberrant ossicles. Conclusions The proposed model has good generalization ability, which highlights the promise of this approach for otologist education, disease diagnosis, and preoperative planning for image-guided otology surgery.

Automated Registration-Based Temporal Bone Computed Tomography Segmentation for Applications in Neurotologic Surgery

Objective This study investigates the accuracy of an automated method to rapidly segment relevant temporal bone anatomy from cone beam computed tomography (CT) images. Implementation of this segmentation pipeline has potential to improve surgical safety and decrease operative time by augmenting preoperative planning and interfacing with image-guided robotic surgical systems. Study Design Descriptive study of predicted segmentations. Setting Academic institution. Methods We have developed a computational pipeline based on the symmetric normalization registration method that predicts segmentations of anatomic structures in temporal bone CT scans using a labeled atlas. To evaluate accuracy, we created a data set by manually labeling relevant anatomic structures (eg, ossicles, labyrinth, facial nerve, external auditory canal, dura) for 16 deidentified high-resolution cone beam temporal bone CT images. Automated segmentations from this pipeline were compared against ground-truth manual segmentations by using modified Hausdorff distances and Dice scores. Runtimes were documented to determine the computational requirements of this method. Results Modified Hausdorff distances and Dice scores between predicted and ground-truth labels were as follows: malleus (0.100 ± 0.054 mm; Dice, 0.827 ± 0.068), incus (0.100 ± 0.033 mm; Dice, 0.837 ± 0.068), stapes (0.157 ± 0.048 mm; Dice, 0.358 ± 0.100), labyrinth (0.169 ± 0.100 mm; Dice, 0.838 ± 0.060), and facial nerve (0.522 ± 0.278 mm; Dice, 0.567 ± 0.130). A quad-core 16GB RAM workstation completed this segmentation pipeline in 10 minutes. Conclusions We demonstrated submillimeter accuracy for automated segmentation of temporal bone anatomy when compared against hand-segmented ground truth using our template registration pipeline. This method is not dependent on the training data volume that plagues many complex deep learning models. Favorable runtime and low computational requirements underscore this method’s translational potential.

Akurasi Gambaran CT Scan Tulang Temporal Preoperatif dalam Menilai Kolesteatoma pada Penderita Otitis Media Supuratif Kronis (OMSK)

This study was aimed to determine the accuracy of preoperative temporal bone CT-scan ini assessing cholesteatoma in chronic suppurative otitis media (CSOM) patients. This was a diagnostic test study conducted by comparing the findings of the preoperative temporal bone CT-scan with the intraoperative findings of 54 CSOM patients who had a temporal bone CT-scan followed by surgery at the Hasanuddin University Hospital and the Jaury Academic Hospital. Assessment of cholesteatoma on a preoperative temporal bone CT-scan was performed when soft tissue density was found in the middle ear accompanied by bone erosion. In addition, an assessment was also carried out for the presence of ossicular, scutum, tympanic tegmen, facial nerve canal and mastoid tegmen erosions. The results indicated that the accuracy of preoperative temporal bone CT-scan in assessing cholesteatoma in CSOM patients was 87.04% with a sensitivity of 85%, specificity of 88.23%, a positive predictive value of 80.95%, and a negative predictive value of 90.91%. The sensitivity of the preoperative temporal bone CT-scan in assessing the highest erosion of cholesteatoma in the erosion of the scutum and tympanic tegmen (100%) with the specificity and accuracy of the preoperative temporal bone CT scan of the in assessing erosions in cholesteatoma highest on mastoid tegman erosion (100% and 96.29%). In conclusion, preoperative CT scan of temporal bone has high accuracy, sensitivity, and specifity values in assessing cholesteatoma and erosions of surrounding structures.Keywords: cholesteatoma, chronic suppurative otitis media (CSOM), temporal bone CT-Scan Abstrak: Penelitian ini bertujuan untuk mengetahui akurasi gambaran CT-scan tulang temporal preoperatif dalam menilai kolesteatoma pada penderita otitis media supuratif kronis (OMSK). Jenis penelitian ialah uji diagnostik yang membandingkan temuan pada CT scan tulang temporal preoperatif dengan hasil temuan intraoperatif pada 54 penderita OMSK yang menjalani pemeriksaan CT scan tulang temporal dilanjutkan dengan tindakan operasi di Rumah Sakit Universitas Hasanuddin dan Rumah Sakit Akademis Jaury. Penilaian kolesteatoma pada CT Scan tulang temporal preoperatif ketika ditemukan densitas jaringan lunak di telinga tengah yang disertai dengan erosi tulang. Selain itu, dilakukan penilaian adanya erosi osikula, skutum, tegmen timpani, kanalis nervus fasialis, dan tegmen mastoid. Hasil penelitian mendapatkan akurasi CT scan tulang temporal preoperatif dalam menilai kolesteatoma pada penderita OMSK sebesar 87,04% dengan sensitivitas 85%, spesifisitas 88,23%, nilai prediksi positif 80,95%, dan nilai prediksi negatif 90,91%. Sensitivitas CT scan tulang temporal preoperatif dalam menilai erosi pada kolesteatoma tertinggi pada erosi skutum dan tegmen timpani (100%) dengan spesifisitas dan akurasi CT scan tulang temporal preoperatif dalam menilai erosi pada kolesteatoma tertinggi pada erosi tegmen mastoid (100% dan 96.29%). Simpulan penelitian ini ialah CT scan tulang temporal preoperatif memiliki nilai akurasi, sensitivitas, serta spesifisitas yang cukup tinggi dalam menilai kolesteatoma serta erosi pada struktur di sekitarnya.Kata kunci: kolesteatoma, otitis media supuratif kronis (OMSK), CT scan tulang temporal

Chronic obstructive Eustachian tube dysfunction: CT assessment with Valsalva maneuver and ETS-7 score

Chronic obstructive Eustachian tube dysfunction (ETD) is a common disorder of the middle ear. In recent years, two main diagnostic tools have become available: Eustachian tube score (ETS-7) and computed tomography (CT) combined with Valsalva maneuver. The aim of this study is to evaluate the outcomes of ETS-7 and CT in a group of patients affected by middle ear atelectasis with a strong suspicion of ETD. Three males and nine females, affected by middle ear atelectasis with retraction of the TM were enrolled. Each patient underwent to Eustachian tube dysfunction evaluation adopting the ETS-7 score and a temporal bone CT with Valsalva maneuver. The ears analyzed at steady state were divided into 2 groups: ETS<7 group and ETS≥ 7 group. The same division was applied for the ears analyzed after the Valsalva maneuver: ETS<7 group and ETS≥ 7 group. ETs were categorized as “well defined” (WD) and “not defined” (ND). The results of the analysis of the ETS-7 score in all 24 ears showed that 42% presented ETS ≥7, while 58% had ETS <7, indicating a diagnosis of ETD. In the ETS<7 group after Valsalva, ET was visualized in 33% of patients. In the ETS≥7 group it was WD in 29% after the Valsalva manoeuver. In both groups the comparison between the visualization of the ET before and after the Valsalva manoeuver did not present a statistical difference. No correlation emerged between ET evaluation with CT scan during Valsalva maneuver and ETS-7 score. It confirms that there is not a gold standard for the study of ET dysfunction.

Cerebrospinal Fluid Leak During Stapes Surgery: The Importance of Temporal Bone CT Reconstructions in Oblique Anatomically Oriented Planes

Stapes gusher is a massive flow of perilymph and cerebrospinal fluid leak that fills the middle ear immediately after surgical opening of the labyrinth, such as during stapedectomy. Stapes gusher usually occurs as the result of a congenital malformation that causes an abnormal communication between the perilymphatic space and the subarachnoid space involving the internal auditory canal or the cochlear duct. To date, the potential risk of stapes gusher cannot be assessed preoperatively, as there are not pathognomonic signs suggestive of this complication. However, high-resolution computed tomography scan (HRCT) of the temporal bone can provide information that may help recognizing patients at risk. Recently, an anatomic evaluation of the inner ear with oblique reformation at HRCT has been described. This reformation offers a new and more detailed topographic vision of temporal bone structures compared to the classic axial and coronal planes and may help identifying anatomical alterations otherwise not visible. In this article, we present a case of stapes gusher and the role of preoperative HRCT with oblique reformation in its prevention.

On the Importance of Proper Window and Level Settings in Temporal Bone CT Imaging

During a discussion on temporal bone imaging, a group of resident trainees in otolaryngology were asked to corroborate the finding of a fracture in set of images that were supposed to be representative of a fracture involving the otic capsule.1 (Figure 1) Their comments included the following statements:“The image still does not clearly identify the fracture. It would have been better if the images were set to the optimal bone window configuration...” “The windowing must be of concern as well. The exposure setting for the non-magnified view is different from the magnified ones. One must observe consistent windowing in order to assess the fractures more accurately.” “...the images which demonstrate a closer look on the otic capsule areas are not rendered in the temporal bone window which makes it difficult to assess.”“...aside from lack of standard windowing...”

Q-tip ear injury with stapes luxation into the vestibule-a case report

<p>Stapediovestibular luxation by Q-tip ear injury is a rare occurrence. The traumatic context associated with cochleovestibular symptoms should lead to a high index of suspiscion. Temporal bone CT scan confirms the diagnosis. The authors report a case of stapediovestibular luxation and discuss the management of this condition. An 8-year-old boy presented to our department for otalgia, hearing loss, and dizziness. The history revealed a penetrating right ear injury by Q-tip, which had occurred 5 days previously. ENT examination found a right peripheral vestibular syndrome with ipsilateral tympanic perforation. Tonal audiometry noted right cophosis. Temporal bone CT scan showed right side internal stapediovestibular dislocation. Middle ear inspection with oval window fistula repair and tympanic closure were performed. Postoperative outcomes showed complete resolution of vestibular symptoms without improvement of sensorineural hearing loss thresholds. Traumatic stapediovestibular dislocation by Q-tip ear injury is unusual. Early diagnosis, with precise lesion assessment and appropriate management resolve vestibular symptoms, prevent infectious complications. But, hearing outcomes are variable.</p><p> </p>