[The value of HRCT in predicting cerebrospinal fluid gusher during cochlear implantation].

Objective:To investigate the predictive value of temporal bone high-resolution CT（HRCT） multiplanar reconstruction（MPR） for cerebrospinal fluid（CSF） gusher during cochlear implantation in patients with inner ear malformation. Methods:The clinical data of 33 patients（36 ears） with inner ear malformation who underwent cochlear implantation were retrospectively analyzed. The predictive value of HRCT for cerebrospinal fluid gusher during cochlear implantation was evaluated. Results:The width of the cochlear foramen（P=0.024, OR=1.735） and the diameter of the inner auditory meatus（P=0.022, OR=6.119） were independent risk factors for CSF gusher during cochlear implantation. The area under the curve（AUC） of cochlear foramen width in predicting intraoperative gusher was 0.851, the sensitivity was 93.33%, and the specificity was 61.90%. The AUC of the upper and lower diameter of the internal auditory canal for predicting intraoperative gusher was 0.848, the sensitivity was 80.00%, and the specificity was 80.95%. The AUC of cochlear foramen width combined with the upper and lower diameters of the internal auditory meatus for predicting intraoperative gusher was 0.930, the sensitivity was 80.00%, and the specificity was 95.24%. Conclusion:Based on temporal bone HRCT, the prediction model of cochlear foramen width combined with the upper and lower diameter of the internal auditory canal has crucial predictive value for the "gusher" during cochlear implantation in patients with inner ear malformation.

A novel radiological software prototype for automatically detecting the inner ear and classifying normal from malformed anatomy.

BACKGROUND: To develop an effective radiological software prototype that could read Digital Imaging and Communications in Medicine (DICOM) files, crop the inner ear automatically based on head computed tomography (CT), and classify normal and inner ear malformation (IEM). METHODS: A retrospective analysis was conducted on 2053 patients from 3 hospitals. We extracted 1200 inner ear CTs for importing, cropping, and training, testing, and validating an artificial intelligence (AI) model. Automated cropping algorithms based on CTs were developed to precisely isolate the inner ear volume. Additionally, a simple graphical user interface (GUI) was implemented for user interaction. Using cropped CTs as input, a deep learning convolutional neural network (DL CNN) with 5-fold cross-validation was used to classify inner ear anatomy as normal or abnormal. Five specific IEM types (cochlear hypoplasia, ossification, incomplete partition types I and III, and common cavity) were included, with data equally distributed between classes. Both the cropping tool and the AI model were extensively validated. RESULTS: The newly developed DICOM viewer/software successfully achieved its objectives: reading CT files, automatically cropping inner ear volumes, and classifying them as normal or malformed. The cropping tool demonstrated an average accuracy of 92.25%. The DL CNN model achieved an area under the curve (AUC) of 0.86 (95% confidence interval: 0.81-0.91). Performance metrics for the AI model were: accuracy (0.812), precision (0.791), recall (0.8), and F1-score (0.766). CONCLUSION: This study successfully developed and validated a fully automated workflow for classifying normal versus abnormal inner ear anatomy using a combination of advanced image processing and deep learning techniques. The tool exhibited good diagnostic accuracy, suggesting its potential application in risk stratification. However, it is crucial to emphasize the need for supervision by qualified medical professionals when utilizing this tool for clinical decision-making.

Deep reinforcement learning and convolutional autoencoders for anomaly detection of congenital inner ear malformations in clinical CT images.

Detection of abnormalities within the inner ear is a challenging task even for experienced clinicians. In this study, we propose an automated method for automatic abnormality detection to provide support for the diagnosis and clinical management of various otological disorders. We propose a framework for inner ear abnormality detection based on deep reinforcement learning for landmark detection which is trained uniquely in normative data. In our approach, we derive two abnormality measurements: Dimage and Uimage. The first measurement, Dimage, is based on the variability of the predicted configuration of a well-defined set of landmarks in a subspace formed by the point distribution model of the location of those landmarks in normative data. We create this subspace using Procrustes shape alignment and Principal Component Analysis projection. The second measurement, Uimage, represents the degree of hesitation of the agents when approaching the final location of the landmarks and is based on the distribution of the predicted Q-values of the model for the last ten states. Finally, we unify these measurements in a combined anomaly measurement called Cimage. We compare our method's performance with a 3D convolutional autoencoder technique for abnormality detection using the patch-based mean squared error between the original and the generated image as a basis for classifying abnormal versus normal anatomies. We compare both approaches and show that our method, based on deep reinforcement learning, shows better detection performance for abnormal anatomies on both an artificial and a real clinical CT dataset of various inner ear malformations with an increase of 11.2% of the area under the ROC curve. Our method also shows more robustness against the heterogeneous quality of the images in our dataset.

[The imaging presentations of the fallopian canal cerebrospinal fluid leaking].

Objective: To summarize the imaging presentations of the fallopian canal cerebrospinal fluid leaking (FCCFL). Methods: The high resolution CT (HRCT)and MRI materials of 4 patients (4 ears) with FCCFL confirmed by surgery between August 2016 to November 2023 were retrospectively analyzed. Among these, there were 2 males and 2 females, their ages ranged from 6 to 69 years. Results: All of the FCCFL were unilateral, including 2 on the left and 2 on the right.Clinically, the patients with FCCFL suffered from clear nasal fluid flow, ear tightness, and hearing loss. On CT, all of the affected ears were depicted markedly dilatation of the proximal portion of fallopian canal(FC), the labyrinthine segment and geniculate fossa were involved in 4 cases, and involvement of tympanic segment in 1 case at the same time. The geniculate fossa in the affected side were significantly enlarged, protruding upwards into the tympanic cavity, with one case simultaneously involving the cochlea. On MRI, the hyposignal on T1WI and hypersignal on T2WI or water sequence like cerebrospinal fluid (CSF) were shown in the enlargement FC, without diffusion restriction, and non-enhancing with administration Gadolinium contrast.CSF-like signal effusion was shown in all of the affected tympanum, of which, the CSF-like signal effusion was demonstrated in the area along the superficial petrosal nerve, the right pterygopalatine fossa and the parapharyngeal space. The adjacent intracranial meninges were presented thickening in 3 cases. Conclusion: The imaging appearances of FCCFL present some characteristics:on HRCT, the proximal portions of the affected FC depicts markedly enlargement,especially the geniculate fossa.While they present CSF-like signal, no diffusion restriction, and no enhancement administration, Gadolinium contrast on MRI, accompanying the CSF-like signal effusion in the affected tympanum.

Inner Ear Breaches from Vestibular Schwannoma Surgery: Revisiting the Incidence of Otologic Injury from Retrosigmoid and Middle Cranial Fossa Approaches.

OBJECTIVE: To assess the rate of iatrogenic injury to the inner ear in vestibular schwannoma resections. STUDY DESIGN: Retrospective case review. SETTING: Multiple academic tertiary care hospitals. PATIENTS: Patients who underwent retrosigmoid or middle cranial fossa approaches for vestibular schwannoma resection between 1993 and 2015. INTERVENTION: Diagnostic with therapeutic implications. MAIN OUTCOME MEASURE: Drilling breach of the inner ear as confirmed by operative note or postoperative computed tomography (CT). RESULTS: 21.5% of patients undergoing either retrosigmoid or middle fossa approaches to the internal auditory canal were identified with a breach of the vestibulocochlear system. Because of the lack of postoperative CT imaging in this cohort, this is likely an underestimation of the true incidence of inner ear breaches. Of all postoperative CT scans reviewed, 51.8% had an inner ear breach. As there may be bias in patients undergoing postoperative CT, a middle figure based on sensitivity analyses estimates the incidence of inner ear breaches from lateral skull base surgery to be 34.7%. CONCLUSIONS: A high percentage of vestibular schwannoma surgeries via retrosigmoid and middle cranial fossa approaches result in drilling breaches of the inner ear. This study reinforces the value of preoperative image analysis for determining risk of inner ear breaches during vestibular schwannoma surgery and the importance of acquiring CT studies postoperatively to evaluate the integrity of the inner ear.

Surgical Considerations in Inner Ear Gene Therapy from Human Temporal Bone Anatomy.

OBJECTIVE(S): Recently directed methods of inner ear drug delivery underscore the necessity for understanding critical anatomical dimensions. This study examines anatomical measurements of the human middle and inner ear relevant for inner ear drug delivery studied with three different imaging modalities. METHODS: Post-mortem human temporal bones were analyzed using human temporal bone histopathology (N = 24), micro computerized tomography (µCT; N = 4), and synchrotron radiation phase-contrast imaging (SR-PCI; N = 7). Nine measurements involving the oval and round windows were performed when relevant anatomical structures were visualized for subsequent age-controlled analysis, and comparisons were made between imaging methods. RESULTS: Combined human temporal bone histopathology showed the mean distance to the saccule from the center of the stapes footplate (FP) was 2.07 ± 0.357 mm and the minimum distance was 1.23 mm. The mean distance from the round window membrane (RWM) to the osseous spiral lamina (OSL) was 1.75 ± 0.199 mm and the minimum distance was 1.43 mm. Instruments inserted up to 1 mm past the center of the FP are unlikely to cause saccular damage, provided there are no endolymphatic hydrops. Similarly, instruments inserted up to 1 mm through the RWM in the trajectory toward the OSL are unlikely to cause OSL damage. CONCLUSION: The combined analyses of inner-ear dimensions of age-controlled groups and imaging modalities demonstrate critical dimensions of importance to consider when inserting delivery vehicles into the human cochlea. LEVEL OF EVIDENCE: N/A Laryngoscope, 134:2879-2888, 2024.

Morphological variability in the inner ear of mice with osteogenesis imperfecta.

Osteogenesis imperfecta (OI) is known to cause hearing loss in ~60% of the affected human population. While OI-related pathologies have been studied in the middle ear, the development of cochlear pathologies is less well understood. In this study, we examine OI-related pathologies of the cochlea in a mouse model of OI to (1) document variation between OI and unaffected mice, and (2) assess the intrusion of the otic capsule onto the cochlea by analyzing differences in duct volumes. Juvenile and adult OIM C57BL/6mice were compared to unaffected wildtype (WT) mice using three-dimensional models of the cochlea generated from high resolution micro-CT scans. Two-tailed Mann-Whitney U tests were then used to investigate duct volume differences both within and between the OI and WT samples. Areas of higher ossification were observed at the cochlear base in the OI sample. OI mice also had significant intraindividual differences in duct volume between right and left ears (4%-15%), an effect not observed in WT mice. WT and OI duct volumes showed a large degree of overlap, although the OIM volumes were more variable. Our findings indicate that OIM mice are likely to exhibit more asymmetry and variation in cochlear volume despite minor differences in sample cochlear volumes, possibly due to bony capsule intrusion. This suggests a potential mechanism of hearing loss, and a high potential for cochlear and otic capsule alteration in OIM mice.

Round Window Niche Veil is Visible on High-Resolution Computed Tomography and a Predictor of Local Drug Efficacy to Inner Ear.

OBJECTIVES: To determine the morphologies and effect of the round window niche veil (RWNV) on local drug delivery efficacy and develop diagnostic criteria on high-resolution computed tomography (HRCT). METHODS: Patients diagnosed with otosclerosis, bilateral profound sensorineural hearing loss or vestibular schwannoma were enrolled from 2019 to 2022, receiving temporal bone HRCT scanning, and anatomic variations of RWMV were summarized intraoperative. For patients with vestibular schwannoma, 1 mL of dexamethasone solution (4 mg/mL) was administered via facial recess during operation, and samples of perilymph were collected to analyze. The diagnostic criteria of RWNV on HRCT were developed and verified. RESULTS: A total of 85 patients were enrolled. RWNV was observed in 54 cases intraoperatively with an incidence of 63.5% (95% CI, 52.9%-73.0%). The median perilymph concentrations were 4.86-fold higher in the group without RWNV than with RWNV (p < 0.0001). RWNV could be visualized on HRCT with a window width of 3500-4500 HU and a window level of 300-500 HU. The characteristic features were as follows: (1) a thin soft tissue shadow could be seen at the entrance of the round window niche (RWN); (2) it was visible in at least 2 consecutive layers along the upper margin of RWN from top to bottom; (3) it was discontinuous with the adjacent bone margin. The sensitivity and specificity of the diagnostic criteria were 77.8% and 93.6%, respectively. CONCLUSION: RWNV could reduce local dexamethasone diffusion efficacy to the inner ear, which could be diagnosed on HRCT and used as a predictor of local drug delivery efficacy to the inner ear. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:1396-1402, 2024.

Congruence and incongruence on the radiological and functional examination of inner ear hemorrhage.

BACKGROUND: Inner ear hemorrhage (IEH) is an increasingly recognized cochlear lesion that can cause sensorineural hearing loss (SNHL). Magnetic resonance imaging (MRI) is known to be the best imaging modality for clarifying the causes of SNHL and providing images that point to those causes. AIMS: Evaluate the lesional patterns in patients with presumed Inner ear hemorrhage (IEH) from radiological and functional aspects. MATERIAL AND METHODS: We retrospectively reviewed 10 patients performed in our institution from 2014 to 2020, with suspected labyrinthine hemorrhage based on radiological and functional examination. RESULTS: We included 8 patients with IEH and sensorineural hearing loss (SNHL). The median age was 55 years (range: 3 months - 78 years). The results from the MRI and functional tests were compared for each end-organ. Only three cases (37.5%) showed a correlation between signal abnormalities and dysfunction in the labyrinthine apparatus. CONCLUSIONS: In patients with SNHL inner ear hemorrhage needs to be ruled out in the differential diagnosis, so specific MRI sequences should be requested. It represents a way to a better understanding of the disorder and the variety of findings claim for a complete auditory and vestibular testing.

Towards fully automated inner ear analysis with deep-learning-based joint segmentation and landmark detection framework.

Automated analysis of the inner ear anatomy in radiological data instead of time-consuming manual assessment is a worthwhile goal that could facilitate preoperative planning and clinical research. We propose a framework encompassing joint semantic segmentation of the inner ear and anatomical landmark detection of helicotrema, oval and round window. A fully automated pipeline with a single, dual-headed volumetric 3D U-Net was implemented, trained and evaluated using manually labeled in-house datasets from cadaveric specimen ([Formula: see text]) and clinical practice ([Formula: see text]). The model robustness was further evaluated on three independent open-source datasets ([Formula: see text] scans) consisting of cadaveric specimen scans. For the in-house datasets, Dice scores of [Formula: see text], intersection-over-union scores of [Formula: see text] and average Hausdorff distances of [Formula: see text] and [Formula: see text] voxel units were achieved. The landmark localization task was performed automatically with an average localization error of [Formula: see text] voxel units. A robust, albeit reduced performance could be attained for the catalogue of three open-source datasets. Results of the ablation studies with 43 mono-parametric variations of the basal architecture and training protocol provided task-optimal parameters for both categories. Ablation studies against single-task variants of the basal architecture showed a clear performance benefit of coupling landmark localization with segmentation and a dataset-dependent performance impact on segmentation ability.

From the morphospace to the soundscape: Exploring the diversity and functional morphology of the fish inner ear, with a focus on elasmobranchsa).

Fishes, including elasmobranchs (sharks, rays, and skates), present an astonishing diversity in inner ear morphologies; however, the functional significance of these variations and how they confer auditory capacity is yet to be resolved. The relationship between inner ear structure and hearing performance is unclear, partly because most of the morphological and biomechanical mechanisms that underlie the hearing functions are complex and poorly known. Here, we present advanced opportunities to document discontinuities in the macroevolutionary trends of a complex biological form, like the inner ear, and test hypotheses regarding what factors may be driving morphological diversity. Three-dimensional (3D) bioimaging, geometric morphometrics, and finite element analysis are methods that can be combined to interrogate the structure-to-function links in elasmobranch fish inner ears. In addition, open-source 3D morphology datasets, advances in phylogenetic comparative methods, and methods for the analysis of highly multidimensional shape data have leveraged these opportunities. Questions that can be explored with this toolkit are identified, the different methods are justified, and remaining challenges are highlighted as avenues for future work.

Imaging Guide to Inner Ear Malformations: An Illustrative Review.

Inner ear malformation (IEM) with associated sensoryneural hearing loss (SNHL) is a major cause of childhood disability. Computed tomography (CT) and magnetic resonance imaging (MRI) imaging play important and often complementary roles in diagnosing underlying structural abnormalities and surgical planning allows for direct visualization of the cochlear nerve and is the preferred imaging modality prior to cochlear implantation. CT is helpful to assess osseous anatomy and when evaluating children with mixed hearing loss or syndromic associations. When reviewing these cases, it is important for the radiologist to be familiar with the key imaging features. In this article, we will present the imaging findings associated with different inner ear malformations associated with congenital sensorineural hearing loss.

Endoscope-Assisted Visualization of the Internal Auditory Canal Using the Middle Fossa Approach.

HYPOTHESIS: Angled endoscopes have been postulated to increase visualization of the internal auditory canal (IAC); however, few studies have quantified the extent of IAC visualization using endoscopes of varying angles. BACKGROUND: Preservation of the bony labyrinth in middle fossa (MF) vestibular schwannoma surgery may limit visualization of the lateral IAC. We sought to determine the extent to which IAC visualization is increased with endoscopes in these situations. METHODS: Computed tomography (CT) scans were acquired before and after two cadaveric MF bony drill-outs. An atlas-based method was used to localize the IAC in the preprocedure CT and then registered with the postprocedure CT using standard image registration methods. Virtual microscope and endoscope positions and angles of approach were determined in a 3D rendering environment. Using ray casting techniques, the percentage of IAC surface area visible (unobscured by bony structures) with the microscope and 0°, 30°, and 45° endoscopes was calculated. RESULTS: For cadaver 1, the microscope led to visible IAC surface areas of 72%, whereas 0°, 30°, and 45° endoscopes visualized 58%, 79%, and 84%, respectively. For cadaver 2, the microscope led to visible surface areas of 67%, whereas the same endoscopes visualized 66%, 84%, and 84%, respectively. CONCLUSIONS: Using a microscope yields similar proportions of visible IAC surface area to a 0° endoscope in MF bony drill-outs. Increased visualization of the IAC is possible with more angled endoscopes. Using angled endoscopes may facilitate improved tumor dissection in the lateral IAC with neural and vascular preservation in vestibular schwannoma surgery aimed at hearing preservation.

MRI surveillance after translabyrinthine vestibular schwannoma resection and cochlear implantation: is it feasible?

PURPOSE: Cochlear implantation in patients with vestibular schwannomas is of increasing importance and interest. Two remaining challenges are the assessment of conduction of the cochlear nerve and the possibility of postoperative surveillance with magnetic resonance imaging. The aim of the current study was to assess follow-up imaging and determine the visibility of the internal auditory canal after vestibular schwannoma resection and cochlear implantation as well as in patients with persistent vestibular schwannomas and cochlear implants in place. Visibility of the internal auditory canal, cerebellopontine angle, and labyrinth were evaluated and graded. METHODS: For this retrospective study, 15 MR examinations of 13 patients after translabyrinthine vestibular schwannoma resection and ipsilateral cochlear implantation were included. All patients had been implanted with an MED-EL cochlear implant. Magnetic resonance imaging was carried out on a 1.5T device. All patients were prepped according to the manufacturer's recommendations. RESULTS: All 15 examinations were carried out without any adverse event during imaging, such as pain, magnet dislocation, or malfunction. The internal auditory canal and the cerebellopontine angle were sufficiently visible in all cases to allow for vestibular schwannoma follow-up. CONCLUSION: Magnetic resonance imaging surveillance of the internal auditory canal following vestibular schwannoma resection and cochlear implantation is feasible and safe with modern implants with a 1.5T magnetic resonance imaging device using metal artifact reduction sequences. Necessary follow-up imaging should not be a contraindication for cochlear implantation in patients with vestibular schwannomas.

Imaging in children with hearing loss. / Bildgebende Diagnostik bei Schwerhörigkeit im Kindesalter.

BACKGROUND: Since the introduction of hearing screening in Germany in 2009, pediatric hearing disorders are detected at an early stage. Early therapy is essential for language development. Imaging plays a central role in diagnosis and therapy planning. METHOD: Imaging findings of the most relevant causes of pediatric hearing disorders are presented. Specific attention is given to the method used in each case - CT or MRI. RESULTS AND CONCLUSIONS: While CT is the method of choice for conductive hearing loss, a combination of CT and MRI with high-resolution T2-3D sequences has been established as the best diagnostic method for sensorineural hearing loss. The most common causes of conductive hearing loss in childhood are chronic inflammation and cholesteatoma. Congenital malformations of the outer or middle ear are less frequent. In the case of sensorineural hearing loss, the cause is located in the inner ear and/or the cochlear nerve or the cerebrum. In these cases, congenital malformations are the most common cause. KEY POINTS: · CT and MRI are necessary to identify morphological causes of hearing disorders and to clarify the possibility of hearing-improving ear surgery or cochlear implantation.. · Contraindications for surgical procedures must be excluded.. · Anatomical variants that may be risk factors for surgery must be described.. CITATION FORMAT: · Sorge I, Hirsch F, Fuchs M et al. Imaging diagnostics for childhood hearing loss. Fortschr Röntgenstr 2023; 195: 896 - 904.

Delayed post gadolinium MRI descriptors for Meniere's disease: a systematic review and meta-analysis.

OBJECTIVES: Delayed post-gadolinium magnetic resonance imaging (MRI) detects changes of endolymphatic hydrops (EH) within the inner ear in Meniere's disease (MD). A systematic review with meta-analysis was conducted to summarise the diagnostic performance of MRI descriptors across the range of MD clinical classifications. MATERIALS AND METHODS: Case-controlled studies documenting the diagnostic performance of MRI descriptors in distinguishing MD ears from asymptomatic ears or ears with other audio-vestibular conditions were identified (MEDLINE, EMBASE, Web of Science, Scopus databases: updated 17/2/2022). Methodological quality was evaluated with Quality Assessment of Diagnostic Accuracy Studies version 2. Results were pooled using a bivariate random-effects model for evaluation of sensitivity, specificity and diagnostic odds ratio (DOR). Meta-regression evaluated sources of heterogeneity, and subgroup analysis for individual clinical classifications was performed. RESULTS: The meta-analysis included 66 unique studies and 3073 ears with MD (mean age 40.2-67.2 years), evaluating 11 MRI descriptors. The combination of increased perilymphatic enhancement (PLE) and EH (3 studies, 122 MD ears) achieved the highest sensitivity (87% (95% CI: 79.92%)) whilst maintaining high specificity (91% (95% CI: 85.95%)). The diagnostic performance of "high grade cochlear EH" and "any EH" descriptors did not significantly differ between monosymptomatic cochlear MD and the latest reference standard for definite MD (p = 0.3; p = 0.09). Potential sources of bias were case-controlled design, unblinded observers and variable reference standard, whilst differing MRI techniques introduced heterogeneity. CONCLUSIONS: The combination of increased PLE and EH optimised sensitivity and specificity for MD, whilst some MRI descriptors also performed well in diagnosing monosymptomatic cochlear MD. KEY POINTS: • A meta-analysis of delayed post-gadolinium magnetic resonance imaging (MRI) for the diagnosis of Meniere's disease is reported for the first time and comprised 66 studies (3073 ears). • Increased enhancement of the perilymphatic space of the inner ear is shown to be a key MRI feature for the diagnosis of Meniere's disease. • MRI diagnosis of Meniere's disease can be usefully applied across a range of clinical classifications including patients with cochlear symptoms alone.

[Imaging evaluation of cerebrospinal fluid otorrhea associated with inner ear malformation in children].

Objective: To explore the imaging evaluation of cerebrospinal fluid (CSF) otorrhea associated with inner ear malformation (IEM) in children. Methods: The clinical data of 28 children with CSF otorrhea associated with IEM confirmed by surgical exploration in Beijing Children's Hospital, from Nov, 2016 to Jan, 2021, were analyzed retrospectively,including 16 boys and 12 girls, aged from 8-month to 15-year and 8-month old, with a median age of 4-year old. The shapes of stapes were observed during the exploration surgery, and the imaging features of temporal bone high resolution CT(HRCT) and inner ear MRI pre- and post-operation were analyzed. Results: In 28 children with CSF otorrhea, 89.3%(25/28) had stapes footplates defect during exploration. Preoperative CT showed indirect signs such as IEM, tympanic membrane bulging, soft tissue in the tympanum and mastoid cavity. IEM included four kinds: incomplete partition type I (IP-Ⅰ), common cavity (CC), incomplete partition type Ⅱ (IP-Ⅱ), and cochlear aplasia (CA); 100%(28/28) presented with vestibule dilation; 85.7%(24/28) with a defect in the lamina cribrosa of the internal auditory canal. The direct diagnostic sign of CSF otorrrhea could be seen in 73.9%(17/23) pre-operative MRI: two T2-weighted hyperintense signals between vestibule and middle ear cavity were connected by slightly lower or mixed intense T2-weighted signals, and obvious in the coronal-plane; 100%(23/23) hyperintense T2-weighted signals in the tympanum connected with those in the Eustachian tube.In post-operative CT, the soft tissues in the tympanum and mastoid cavity decreased or disappeared as early as one week. In post-operative MRI, the hyperintense T2-weighted signals of tympanum and mastoid decreased or disappeared in 3 days to 1 month,soft tissues tamponade with moderate intense T2-weighted signal were seen in the vestibule in 1-4 months. Conclusions: IP-Ⅰ, CC, IP-Ⅱ and CA with dilated vestibule can lead to CSF otorrhea. Combined with special medical history, T2-weighted signal of inner ear MRI can provide diagnostic basie for most children with IEM and CSF otorrhea.HRCT and MRI of inner ear can also be used to evaluate the effect of surgery.

Behavioral and functional assessment of mice inner ear after chronic exposure to an ultrahigh B0 field of 11.7 T or 17.2 T.

PURPOSE: Assess short-term and long-term effects of chronic exposure to an ultrahigh static magnetic (B0 ) field on mice inner ear in the context of MR safety of human scanning at 11.7 T. METHODS: Mice were chronically exposed to a B0 field of 11.7 T or 17.2 T during ten 2-h exposure sessions evenly distributed over a period of 5 weeks, resulting in a total of 20 h of exposure per mouse. During exposure sessions, mice were anesthetized and positioned either parallel or antiparallel to B0 . Before, during, and 2 weeks after the magnetic-field exposure period, mice performed behavioral tests (balance beam, rotarod, and swim tests) to evaluate their short-term and long-term motor coordination and balance. An auditory brainstem response (ABR) test was finally performed to assess the functional integrity of mice cochlea, 2 weeks after the last exposure. RESULTS: After awaking from anesthesia following B0 exposures at 11.7 Tor 17.2 T, mice displayed a transient (<5 min) rotating behavior. The behavioral tests did not show any difference between the exposed and the control mice at any time point. Determination of ABR thresholds did not reveal an impairment of cochlea hair cells resulting from chronic B0 exposure. CONCLUSION: Despite the transient disturbance of mice vestibular system observed immediately after B0 exposure, no short-term nor long-term alteration was detected with behavioral and ABR tests.