Temporal Bone Computed Tomography Research Articles

Cochlear Nerve Deficiency in Pediatric Unilateral Hearing Loss and Asymmetric Hearing Loss

Introduction: The rates of cochlear nerve abnormalities and cochlear malformations in pediatric unilateral hearing loss (UHL) are conflicting in the literature, with important implications on management. The aim of this study was to investigate the incidence of cochlear nerve deficiency (CND) in pediatric subjects with UHL or asymmetric hearing loss (AHL). Methods: A retrospective chart review of pediatric subjects <18 years of age evaluated for UHL or AHL with fine-cut heavily T2-weighted magnetic resonance imaging (MRI) between January 2014 and October 2019 (n = 291) at a tertiary referral center was conducted. MRI brain and computed tomography temporal bone were reviewed for the presence of inner ear malformations and/or CND. Status of the ipsilateral cochlear nerve and inner ear was evaluated. Pure tone average (PTA) at 500, 1,000 and 2,000 Hz was assessed. Results: 204 subjects with UHL and 87 subjects with AHL were included. CND (aplasia or hypoplasia) was demonstrated in 61 pediatric subjects with UHL (29.9%) and 10 with AHL (11.5%). Ipsilateral cochlear malformations were noted in 25 subjects with UHL (12.3%) and 11 with AHL (12.6%), and ipsilateral vestibular malformations in 23 (11.3%) and 12 (13.8%) ears, respectively. Median PTA was statistically significantly higher in ears with CND (98.33) than ears with normal nerves (90.84). Discussion/Conclusion: Imaging demonstrated a high incidence of inner ear malformations, particularly CND, in pediatric subjects with UHL. Auditory findings indicated CND cannot be ruled out by thresholds alone as some CND ears did demonstrate measurable hearing. Radiologic evaluation by MRI should be performed in all patients within this population to guide counseling and management of hearing loss based on etiology, with implications on candidacy for cochlear implantation.

Laboratory and imaging findings of necrotizing otitis externa are associated with pathogen type and disease outcome: A retrospective analysis.

To examine associations of laboratory and imaging data with diagnostic parameters of necrotizing otitis externa (NOE) and its severity, and to compare between bacterial and fungal infections. Records of patients diagnosed with NOE during 2010-2018 at the Department of Otolaryngology, Head and Neck Surgery were reviewed retrospectively for demographics; disease characteristics; and laboratory, scintigraphy, and imaging results. Of 48 patients with NOE, the mean age is 73±11.6years; 32 (67%) were males; 83% had diabetes mellitus. Common pathogens were pseudomonas (49%) and fungi (33%). Sensitivities of the technetium-scan (SPECT ratio ≥1.5), temporal bone computed tomography (CT), and gallium-scan (SPECT ratio ≥1.3) were: 78.7%, 48.8%, and 31.4%, respectively. Gallium-scan results correlated positively with CT bone involvement (p=0.002) and hospital length of stay (p=0.0014). C-reactive protein (CRP) level correlated with hospital length of stay (p=0.028) and positive technetium-scan results (p=0.012). Fungal infection had a higher technetium SPECT ratio (2.16 vs. 1.77, p=0.04), gallium SPECT ratio (1.4 vs. 1.2, p=0.02), longer duration of systemic treatment (87.4 vs. 37.9days, p=0.014), and longer hospital length of stay (31.6 vs. 15.2days, p=0.004) compared to non-fungal infection. Eight (17%) patients had responded poorly to treatment. Fungal pathogens, facial nerve paresis, extra-auricular, and bilateral disease were more prevalent among the non-responders. The technetium scan has higher sensitivity than temporal bone CT for diagnosing NOE. The gallium scan and CRP correlated well with hospital length of stay. A high rate of fungal infection was found, with significantly higher technetium and gallium SPECT ratios and worse outcome compared to bacterial infection. Fungal NOE remains therapeutically challenging.

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

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.

Utility of Temporal Bone Computed Tomography in Pediatric Emergency Medicine.

ObjectiveTemporal bone computed tomography (CT) requires a relatively high radiation dose to produce high-resolution images required to define surgical anatomy. In the acute setting, the need for this detailed evaluation of temporal bone pathology may not be required for nonsurgical management and clinical decision-making. We performed a retrospective review of the clinical characteristics and subsequent management of children who underwent CT of the temporal bone with the goal of optimizing clinical decision-making and mitigating the risks of radiation exposure in children.MethodsWe included pediatric patients (<18 years of age) with International Classification of Diseases (9th or 10th revision) diagnoses consistent with otitis externa, otitis media, mastoiditis, head trauma, temporal bone fracture, and otalgia who were treated in the emergency department and underwent temporal bone CT from January 1, 2012–December 31, 2016. We collected data regarding the patients’ presenting symptoms, physical exam findings, indications for imaging, radiographic findings, disposition, and operative intervention within 30 days of imaging. Features of the suspected mastoiditis group were compared between operative and non-operative patients.ResultsOver the four-year study period there were 96 temporal bone CTs. Most studies (70%) were associated with a subsequent inpatient admission. Common indications for imaging included evaluation of acute mastoiditis (55%) or trauma (41%). Of the 53 patients with concern for mastoiditis, 27 (51%) required otologic surgery. Two patients in the trauma group required surgical intervention, both for facial nerve decompression. In patients with suspected mastoiditis, mental status changes (P = 0.02), auricular proptosis (P = 0.05), and fluctuance (P = 0.02) were significantly more prevalent in the operative group; however, no other findings were significantly associated with operative intervention.ConclusionTemporal bone CT is beneficial in guiding diagnosis and management of acute mastoiditis. We found that a majority of patients with suspected mastoiditis who underwent temporal bone CT ultimately required surgery or hospital admission. However, the potential for reduction in the use of CT still exists in this population. Fractures of the temporal bone typically do not require urgent operative intervention in the absence of complete facial nerve paralysis; thus, the utility of temporal bone CT in trauma evaluation may be limited.

High-Resolution CT Imaging of the Temporal Bone: A Cadaveric Specimen Study.

Objective Super-high and ultra-high spatial resolution computed tomography (CT) imaging can be advantageous for detecting temporal bone pathology and guiding treatment strategies. Methods Six temporal bone cadaveric specimens were used to evaluate the temporal bone microanatomic structures utilizing the following CT reconstruction modes: normal resolution (NR, 0.5-mm slice thickness, 512 2 matrix), high resolution (HR, 0.5-mm slice thickness, 1,024 2 matrix), super-high resolution (SHR, 0.25-mm slice thickness, 1,024 2 matrix), and ultra-high resolution (UHR, 0.25-mm slice thickness, 2,048 2 matrix). Noise and signal-to-noise ratio (SNR) for bone and air were measured at each reconstruction mode. Two observers assessed visualization of seven small anatomic structures using a 4-point scale at each reconstruction mode. Results Noise was significantly higher and SNR significantly lower with increases in spatial resolution (NR, HR, and SHR). There was no statistical difference between SHR and UHR imaging with regard to noise and SNR. There was significantly improved visibility of all temporal bone osseous structures of interest with SHR and UHR imaging relative to NR imaging ( p < 0.001) and most of the temporal bone osseous structures relative to HR imaging. There was no statistical difference in the subjective image quality between SHR and UHR imaging of the temporal bone ( p ≥ 0.085). Conclusion Super-high-resolution and ultra-high-resolution CT imaging results in significant improvement in image quality compared with normal-resolution and high-resolution CT imaging of the temporal bone. This preliminary study also demonstrates equivalency between super-high and ultra-high spatial resolution temporal bone CT imaging protocols for clinical use.

Non-Echoplanar Diffusion Weighted Imaging and 3D Fiesta Magnetic Resonance Imaging Sequences with High Resolution Computed Tomography Temporal Bone in Assessment and Predicting the Outcome of Chronic Suppurative Otitis Media with Cholesteatoma

Introduction: Cholesteatomas are lesions that develop in pneumatized areas of the temporal bone, such as the middle ear and mastoid, or both, and are extremely rarely detected in the external auditory canal. Because it has benefits over CT, diffusion weighted imaging MRI (DWI-MRI) can be a useful technique in the identification of cholesteatoma. Image distortion and artefacts are less visible with non-echo planar imaging DWI techniques than with other DWI techniques. Aims and Objectives: 1) To assess the usefulness of HRCT scan in Chronic suppurative otitis media (CSOM) with cholesteatoma in depicting the status of the middle ear structures. 2) To correlate HRCT findings of temporal bone with surgical findings in Chronic suppurative otitis media (CSOM) with cholesteatoma with respect to the following parameters: Presence or absence of cholesteatoma, Extent of cholesteatoma, Status of ossicular chain, Integrity of the facial canal, Detection of erosions or dehisence in the bony labyrinth, and Detection of erosions or dehisence in the dural or sinus plates. 3) Comparison with Non Echo planar imaging diffusion weighted for presence or absence of cholesteatoma. 4) 3D FIESTA Magnetic resonance imaging with 3D reconstruction of membranous vestibule and cochlea for better delineating associated complications. Materials and Methods: Total 40 patients of clinically suspected CSOM with cholestaetoma were enrolled for this study. All patients were scanned using a non-contrast High-resolution computed tomography technique and MRI. HRCT findings were noted according to the proforma. MRI DWI was recorded as either positive or negative for cholesteatoma &amp; directly correlated with post-surgical presence or absence of cholesteatoma.3D FIESTA for detection of membranous labyrinthine erosion/defect was correlated with surgical findings of bony labyrinthine erosions. Results: Cholesteatoma was shown to be common in the third decade of life in our study. The most often implicated middle ear structures in our investigation were the epitympanum, aditus, and antrum. The most often eroded ossicle is the stapes, followed by the incus. The tympanic section of the facial canal is the most often affected segment, while the posterior semicircular canal is the most commonly degraded of the bony labyrinth structures. Conclusion: HRCT temporal bone, in combination with non-echoplanar DWI MRI and 3D Fiesta, can help with accurate diagnosis and pre-operative assessment of cholesteatoma.

Congenital atresia of external auditory canal with choristoma: A rare case report

Congenital aural atresia (CAA) is the abnormality of the auricle and/or external auditory canal where there is closure of the external auditory canal which may be associated with microtia and anomalies in the middle ear, inner ear, or temporal bone. It can be solid or membranous type of atresia. To identify the type of defect, high-resolution computed tomography (HRCT) temporal bone is useful. After identifying the defect, the patient can be planned for canaloplasty or atresiaplasty with split skin graft. A 6-year-old boy was brought to the otorhinolaryngology outpatient department with complaints of deformity of the left ear since birth. HRCT temporal bone showed isolated left external auditory canal atresia. Echocardiogram showed dextrocardia with situs solitus and USG abdomen revealed situs inversus of the abdominal organs with no significant abnormality. After proper evaluation of the child, after obtaining preanesthetic fitness, the child had undergone atresiaplasty with split skin graft under general anesthesia. Soft tissue that was excised from the external auditory canal was sent for histopathological examination, which revealed the presence of salivary gland tissue with lymph nodes showing reactive changes. These features were suggestive of possibility of choristoma of the left external auditory canal. CAA occurs in the defect during embryological development which may result in deformity of the auricle and external auditory canal. The surgical management of congenital external auditory canal atresia is atresiaplasty, and hearing rehabilitation (bone anchored hearing aid) should be given in case of no improvement in hearing. The surgery will be challenging because of altered anatomy of surgical landmarks. Choristoma is a tumor-like growth of normal tissue in an abnormal place. It is a benign condition, which may be found commonly in the head-and-neck region such as presence of salivary gland tissue in the middle ear, presence of gastric mucosa in the tongue and presence of osseous or cartilaginous masses in the intraoral soft tissues. Total excision can be done for small and pedunculated tumors, and care should be taken not to injure facial nerve. CAA may not necessarily present with deformities in the external ear (pinna), but Congenital aural atresia cases may not always present with deformities of the pinna,but it is crucial not to miss such cases. These patients may be evaluated by doing High Resolution Computed Tomography temporal bone and audiometric assessment such as. Pediatric evaluation is equally important to rule out for any syndromic association. Atresiaplasty or canaloplasty has shown great result for correcting the cosmetic defect. Hearing can be facilitated further using bone anchored hearing aids or cochlear implantation.

Diagnostic value of multi-slice spiral CT in tympanic wall destruction of middle ear cholesteatoma

Objective:To investigate the correlation between preoperative temporal bone Computed Tomography （CT） findings and intraoperative manifestations in patients with middle ear cholesteatoma. Methods:The patients with cholesteatoma undergoing surgery in our hospital from March 2017 to November 2020 were retrospectively analyzed.The temporal bone CT findings of tympanoid wall status before operation and the state of tympanic wall during operation were compared. Results: A total of 148 cases （148 ears） were included in the analysis. Compared with intraoperative observation, 142 cases showed the same findings of tympanoid lid by preoperative CT examination, and 144 cases showed the same findings of mastoid lid by preoperative CT examination.The CT manifestations of facial nerve canal state in 18 patients was different from intraoperativen findings. Among the 12 cases of lateral wall destruction of the tympanic chamber observed by CT, 10 cases were consistent with the intraoperative findings.CT showed sigmoid sinus destruction in 6 cases, of which 5 cases were consistent with intraoperative findings. In 142 cases no sigmoid sinus destruction was found by CT , but in one case the CT findingswas different from intraoperative findings.The diagnostic efficiency of the exposed opposite neural tube was poor in the tympanoid wall observed by CT（Se=78.6%，Sp=90.0%，PPV=64.7%，NPV=94.7%，AUC=0.84，Kappa=0.63，P<0.05）, but the diagnostic efficiency of lateral wall failure of the drum chamber was good （Se=83.5%，Sp=98.5%，PPV=83.3%，NPV=98.6%，AUC=0.91，Kappa=0.82，P<0.05）. Conclusion:CT is effective in preoperative diagnosing of tympanic wall destruction caused by cholesteatoma of the middle ear, especially in detecting the destruction of tympanic lid, mastoid lid, lateral wall of the tympanic chamber and sigmoid sinus.Preoperative temporal bone CT scan is beneficial to clincal preoperative decision-making and intraoperative guidance.

Pneumolabyrinth as an Early Computed Tomographic Finding After Cochlear Implantation and its Clinical Significance.

To determine the incidence and volume of pneumolabyrinth using early temporal bone computed tomography (TBCT) findings and evaluate the correlation between pneumolabyrinth and various clinical variables. Retrospective case review. Tertiary academic center. Fifty-three consecutive adult cochlear implantation (CI) recipients (53 ears) with normal inner ears who underwent high-resolution TBCT within 3 days after CI were included. Axial TBCT images were used for detection and measurement of pneumolabyrinth. Incidence and volume of pneumolabyrinth were evaluated. In addition, the following clinical variables were analyzed to evaluate the correlation with pneumolabyrinth volume: demographics, implant type, surgical approach, postoperative dizziness, and preservation of functional residual hearing. Pneumolabyrinth was present in all patients, and the average volume was 8.496 mm3. Pneumolabyrinth was confined to the cochlea (pneumocochlea) in all patients except for one who also had pneumovestibule. The pneumolabyrinth volume in patients with postoperative dizziness was significantly larger than that in patients without postoperative dizziness (10.435 mm3 vs. 8.016 mm3; p = 0.029). Multivariate analysis showed that a larger volume of pneumolabyrinth was significantly associated with postoperative dizziness (odds ratio, 1.420; 95% confidence interval, 1.114-1.808; p = 0.005). A certain volume of pneumolabyrinth was always present in the early stage after CI, and the volume of pneumolabyrinth measured using early TBCT findings was significantly associated with the occurrence of postoperative dizziness.

Temporal bone computed tomography checklist-TeSLANO: introduction of a standardized preoperative imaging evaluation for middle ear surgery.

Aim of the study was to evaluate if the introduction of the imaging checklist TeSLANO would improve the identification of crucial anatomical findings from temporal bone computed tomography (TBCT) scans among a cohort of Otolaryngology residents. Single-blinded prospective cohort study. Tertiary care university hospital and referral center for otology and skull base surgery. The cohort was composed by eight Otorhinolaryngology residents (four junior and four senior) that were individually asked to identify all relevant anatomic findings from preoperative TBCT scans. Supervising surgeon showed to each resident four TBCT scans before and four after the introduction of a systematic checklist evaluation system based on the TeSLANO acronym. Statistical analysis was performed using McNemar's test and results were considered significant with a P value < 0.05. Introduction of the checklist improved global identification of critical anatomical structures from 48.75 to 89.17% (P < 0.05). The postimplementation identification percentage improved for both the senior and junior groups (P < 0.05). The imaging checklist TeSLANO allows a systematic approach to review TBCT scans and significantly improves identification of critical anatomical structures in Otorhinolaryngology residents.

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

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. Descriptive study of predicted segmentations. Academic institution. 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. 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. 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.

A novel view of computed tomography images similar to the visual field of otologic surgeons.

ObjectivesIn preparation for endoscopic sinus surgery (ESS), the most important computed tomography (CT) image for otolaryngologists is the coronal plane image because it has a viewpoint similar to that of the surgical visual field. Contrastingly, otologic surgeons refer to axial and coronal plane images before ear surgery and must imagine the anatomical structure of the temporal bone by reconstructing three‐dimensional (3D) images in their minds. We propose a “surgical position view (SPV) image,” a novel viewpoint of CT images that enables otologic surgeons to see a perspective similar to the surgical visual field.MethodSagittal plane CT images of the temporal bone were created from axial plane images with multi‐planar reconstruction (MPR). Then, the SPV image was obtained by rotating it 90° to the supine position. The entire process can be performed anywhere in the hospital within 1 minute using the electronic medical record computer's image viewer.ResultsSPV images show anatomical structures of the temporal bone, external ear canal, mastoid cavity, sigmoid vein, facial nerve, ossicles, and cochlea, in a similar view to the actual ear surgery. Soft tissue such as cholesteatoma is depicted in the same concentration as the normal CT image.ConclusionThe SPV image enables an otologic surgeon to see the temporal bone CT image from the actual ear surgery viewpoint simply and quickly. It helps to visualize the 3D anatomical structure of the temporal bone and can be useful for ear surgery planning.Level of evidence5

3D Exoscope Navigation-Guided Approach to Middle Cranial Fossa.

To test the feasibility and efficacy of a 3D exoscope navigation-guided middle cranial fossa (MCF) approach to the internal auditory canal (IAC); to potentially obviate the need to use dissection landmarks and instead, use the navigation probe as a guide to find structures and drill down to the IAC. Cadaveric dissection of six temporal bones. Computed tomography temporal bone was performed with fiducials on each specimen before the dissection to employ the navigation system. Using a 3D exoscope with navigation by Synaptive (Toronto, Ontario, Canada), the MCF approach was performed. Navigation accuracy, ability to identify critical structures, and ability to drill out the IAC successfully. All six specimens had the IAC successfully drilled out using the 3D exoscope. All dissections were performed with navigation and did not require dissecting out the greater superficial petrosal nerve and superior semicircular canal. One specimen used landmark dissection to confirm the IAC after navigation had been used to locate the IAC first. Navigation accuracy mean was 1.86 mm (range, 1.56-2.05 mm). A 3D exoscope navigation-guided MCF approach to the IAC is feasible without landmark dissection.

What's Your Diagnosis? Symptoms: Ear Pain and Chronic Ear Drainage

What's Your Diagnosis? Symptoms: Ear Pain and Chronic Ear Drainage

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.

New Compartmental Reading Method for MRI Enables Accurate Localization of Cholesteatomas With High Sensitivity and Specificity.

Cholesteatoma is an inflammatory disease, frequently observed in childrens and young adults, with a risk of relapse or recurrence. The few studies which analyzed cholesteatoma localization on magnetic resonance imaging (MRI) usually merged CT-MR images or relied on their authors' anatomical knowledge. We propose a compartmental reading method of the compartments of the middle ear cavity for an accurate localization of cholesteatomas on MR images alone. Our method uses easily recognizable anatomical landmarks, seen on both computed tomography (CT) and MRI, to delimit the middle ear compartments (epitympanum, mesotympanum, hypotympanum, retrotympanum, protympanum, antrum-mastoid cavity). We first tested it on 50 patients on non-enhanced temporal bone CT. Then, we evaluated its performances for the localization of cholesteatomas on MRI, compared with surgery on 31 patients (validation cohort). The selected anatomical landmarks that delimited the middle ear compartments were applicable in 98 to 100% of the cases. In the validation cohort, we were able to accurately localize the cholesteatoma on MRI in 83% of the cases (n = 26) with high sensitivity (95.7%) and specificity (98.6%). With our compartmental reading method, based on the recognition of well-known anatomical landmarks to differentiate the compartments of the middle ear cavity on MRI, we were able to accurately localize the cholesteatoma with high (>90%) sensitivity and specificity. Such landmarks are widely applicable and only require limited learning time based on key images. Accurate localization of the cholesteatoma is useful for the choice of surgical approach.

Computed-Tomography-Structured Reporting in Middle Ear Opacification: Surgical Results and Clinical Considerations From a Large Retrospective Analysis.

Purpose: The aim of the study is to compare the accuracy of unstructured preoperative Computed Tomography (CT) reports from non-tertiary diagnostic centers with intraoperative findings in a large cohort of patients with Chronic Otitis Media (COM) undergone surgery.Methods: From 2012 to 2019, a total number of 301 patients were considered for our purposes. All patients with clinical evidence of COM had preoperative non-contrast high resolution CT scan of the temporal bone in non-tertiary diagnostic centers, performed within 3 months before surgery.Results: The accuracy of CT reports was analyzed in terms of nature, anatomical site, disease extension, bony erosion, vascular structures abnormalities relevant to surgical planning, and Eustachian tube patency. Compared to post-surgical findings, CT reporting critical analysis revealed a tendency to overestimation of bony erosion, coupled to underestimated description of facial canal/lateral semi-circular canal, vascular structures, and Eustachian tube.Conclusion: Discrepancies between CT reports and surgical findings in middle ear opacification can be at least in part due to limited expertise of general radiologists in ENT neuroimaging. To limit this lack of information and the limited accuracy of middle ear structures depiction, here we propose a structured checklist to adopt in the case of a temporal bone CT scan for COM, in order to optimize the communication with surgeons and provide all the crucial information for an accurate surgical planning.

The Diagnostic Efficacy of MRI in the Evaluation of the Enlarged Vestibular Aqueduct in Children with Hearing Loss.

The aim of our study is to evaluate the diagnostic effectiveness of magnetic resonance imaging (MRI) compared to computed tomography (CT) in the detection of enlarged vestibular aqueduct (EVA) in childhood. One hundred twenty-three children who underwent temporal bone CT and MRI examinations for hearing loss between 2013 and 2020 were evaluated retrospectively. All CT and MRI images were examined by two pediatric radiologists, according to the Valvassori and Cincinnati criteria for EVA. Imaging findings on CT and MRI of the vestibular aqueduct were recorded. Two pediatric radiologists performed the measurements for EVA on CT and MRI. In addition, an otolaryngologist performed the measurements independently. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MRI compared to CT were calculated to detect EVA. The difference between the measurements on CT and MRI was investigated. The inter-observer agreement was evaluated for measurements. The mean age of 123 children (65 boys and 58 girls) was 50.18±50.40 months. Two hundred forty-six ears were evaluated in 123 children. On CT images, EVA was present in 28 (11.3%) of 246 ears according to Cincinnati criteria and 27 (10.9%) of 246 ears according to Valvassori criteria, respectively. While sensitivity, specificity, PPD, and NPD rates of MRI were 100%, 99%, 92.8%, and 100%, respectively, for Cincinnati criteria, for Valvassori criteria, they were 100%, 97.3%, 77.7%, and 100%, respectively. According to the visual evaluation performed without using measurement, the enlarged appearance of the vestibular aqueduct was significant for the diagnosis of EVA (p<0.001), while the absence of this appearance was significant for the exclusion of EVA (p<0.001). There was no significant difference between the measurements on CT and MRI. There was a perfect correlation between the observers for measurements. MRI can be used as an initial imaging technique in children with suspicion of EVA to reduce radiation exposure.

Fully automated preoperative segmentation of temporal bone structures from clinical CT scans

Middle- and inner-ear surgery is a vital treatment option in hearing loss, infections, and tumors of the lateral skull base. Segmentation of otologic structures from computed tomography (CT) has many potential applications for improving surgical planning but can be an arduous and time-consuming task. We propose an end-to-end solution for the automated segmentation of temporal bone CT using convolutional neural networks (CNN). Using 150 manually segmented CT scans, a comparison of 3 CNN models (AH-Net, U-Net, ResNet) was conducted to compare Dice coefficient, Hausdorff distance, and speed of segmentation of the inner ear, ossicles, facial nerve and sigmoid sinus. Using AH-Net, the Dice coefficient was 0.91 for the inner ear; 0.85 for the ossicles; 0.75 for the facial nerve; and 0.86 for the sigmoid sinus. The average Hausdorff distance was 0.25, 0.21, 0.24 and 0.45 mm, respectively. Blinded experts assessed the accuracy of both techniques, and there was no statistical difference between the ratings for the two methods (p = 0.93). Objective and subjective assessment confirm good correlation between automated segmentation of otologic structures and manual segmentation performed by a specialist. This end-to-end automated segmentation pipeline can help to advance the systematic application of augmented reality, simulation, and automation in otologic procedures.

Role of High-Resolution Computed Tomography Temporal Bone in Evaluation of Patients with Chronic Suppurative Otitis Media (CSOM)

Role of High-Resolution Computed Tomography Temporal Bone in Evaluation of Patients with Chronic Suppurative Otitis Media (CSOM)