Imaging of Pathologies of the Temporal Bone and Middle Ear: Inflammatory Diseases, Their Mimics and Potential Complications-Pictorial Review.

Imaging of the temporal bone and middle ear is challenging for radiologists due to the abundance of distinct anatomical structures and the plethora of possible pathologies. The basis for a precise diagnosis is knowledge of the underlying anatomy as well as the clinical presentation and the individual patient's otological status. In this article, we aimed to summarize the most common inflammatory lesions of the temporal bone and middle ear, describe their specific imaging characteristics, and highlight their differential diagnoses. First, we introduce anatomical and imaging fundamentals. Additionally, a point-to-point comparison of the radiological and histological features of the wide spectrum of inflammatory diseases of the temporal bone and middle ear in context with a review of the current literature and current trends is given.

Evaluating the generalizability of deep learning image classification algorithms to detect middle ear disease using otoscopy.

To evaluate the generalizability of artificial intelligence (AI) algorithms that use deep learning methods to identify middle ear disease from otoscopic images, between internal to external performance. 1842 otoscopic images were collected from three independent sources: (a) Van, Turkey, (b) Santiago, Chile, and (c) Ohio, USA. Diagnostic categories consisted of (i) normal or (ii) abnormal. Deep learning methods were used to develop models to evaluate internal and external performance, using area under the curve (AUC) estimates. A pooled assessment was performed by combining all cohorts together with fivefold cross validation. AI-otoscopy algorithms achieved high internal performance (mean AUC: 0.95, 95%CI: 0.80-1.00). However, performance was reduced when tested on external otoscopic images not used for training (mean AUC: 0.76, 95%CI: 0.61-0.91). Overall, external performance was significantly lower than internal performance (mean difference in AUC: -0.19, p ≤ 0.04). Combining cohorts achieved a substantial pooled performance (AUC: 0.96, standard error: 0.01). Internally applied algorithms for otoscopy performed well to identify middle ear disease from otoscopy images. However, external performance was reduced when applied to new test cohorts. Further efforts are required to explore data augmentation and pre-processing techniques that might improve external performance and develop a robust, generalizable algorithm for real-world clinical applications.

Quiste epidermoide en conducto auditivo externo: reporte de caso / Epidermoid cysts of the external auditory canal: case report

Resumen El quiste epidérmico es una lesión benigna y común de la piel. Se desarrolla por un bloqueo de la unidad pilosebácea, con la consecuente proliferación de células epiteliales y secuestro de queratina. El 7% se desarrollan en cabeza y cuello, sin embargo, son infrecuentes en canal auditivo externo. Su patrón de crecimiento es lento y progresivo durante años, siendo asintomáticos. Al aumentar de tamaño causan sintomatología variable, acorde a su localización; en el canal auditivo tienen un comportamiento obstructivo que genera síntomas como otalgia e hipoacusia. Se presenta caso de una paciente de 69 años, con acúfeno e hipoacusia progresiva derecha. Durante la otoscopia se observó una neoformación obstructiva del 100% de la luz del conducto. Se realizaron estudios de imagen que reportaron tumoración de características quísticas de conducto auditivo derecho, bien circunscrita, sin erosión ósea. Para el diagnóstico definitivo, se realizó resección quirúrgica y biopsia reportando quiste epidérmico. Durante el seguimiento posoperatorio sin hallazgos de recidiva.

Abstract The epidermal cyst is a common and benign lesion of the skin. It develops due to a blockage of the pilosebaceous unit, with the consequent proliferation of epithelial cells and keratin sequestration. Seven percent develop in the head and neck; however, they are infrequent in the external auditory canal. Its growth pattern is slow and progressive over the years, being asymptomatic. As they increase in size, they cause variable symptoms, according to their location. In the ear canal they have an obstructive behavior that generates symptoms such as earache and hearing loss. A case of a 69-year-old female with tinnitus and progressive right hearing loss is presented. At otoscopy, a 100% obstructive neoformation of the canal lumen was observed. Imaging studies showed a well circumscribed, cystic tumor of the right ear canal, without bone erosion. For the definitive diagnosis, a resection and biopsy were performed, reporting an epidermal cyst. During follow up there was no recurrence of tumor.

An Artificial Intelligence Computer-vision Algorithm to Triage Otoscopic Images From Australian Aboriginal and Torres Strait Islander Children.

OBJECTIVE: To develop an artificial intelligence image classification algorithm to triage otoscopic images from rural and remote Australian Aboriginal and Torres Strait Islander children. STUDY DESIGN: Retrospective observational study. SETTING: Tertiary referral center. PATIENTS: Rural and remote Aboriginal and Torres Strait Islander children who underwent tele-otology ear health screening in the Northern Territory, Australia between 2010 and 2018. INTERVENTIONS: Otoscopic images were labeled by otolaryngologists to classify the ground truth. Deep and transfer learning methods were used to develop an image classification algorithm. MAIN OUTCOME MEASURES: Accuracy, sensitivity, specificity, positive predictive value, negative predictive value, area under the curve (AUC) of the resultant algorithm compared with the ground truth. RESULTS: Six thousand five hundred twenty seven images were used (5927 images for training and 600 for testing). The algorithm achieved an accuracy of 99.3% for acute otitis media, 96.3% for chronic otitis media, 77.8% for otitis media with effusion (OME), and 98.2% to classify wax/obstructed canal. To differentiate between multiple diagnoses, the algorithm achieved 74.4 to 92.8% accuracy and an AUC of 0.963 to 0.997. The most common incorrect classification pattern was OME misclassified as normal tympanic membranes. CONCLUSIONS: The paucity of access to tertiary otolaryngology care for rural and remote Aboriginal and Torres Strait Islander communities may contribute to an under-identification of ear disease. Computer vision image classification algorithms can accurately classify ear disease from otoscopic images of Indigenous Australian children. In the future, a validated algorithm may integrate with existing telemedicine initiatives to support effective triage and facilitate early treatment and referral.

Enlargement of Eustachian Tube Lumen in Patulous Eustachian Tube Patients Compared to that by Aging.

OBJECTIVE: To evaluate the Eustachian tube (ET) dimensions in patulous ET (PET) patients compared with that by aging using sitting 3D computed tomography (CT). STUDY DESIGN: Retrospective study. SETTING: Tertiary referral center. SUBJECTS AND METHODS: A retrospective survey of medical records in Sen-En Rifu Hospital identified 105 ears of 76 PET patients and 65 ears of 34 patients without ET dysfunction findings (non-PET). Subjects in both PET and non-PET groups were then divided into two age groups. Groups A and C defined as non-PET and PET subjects respectively, who were under the age of 60 years, while Groups B and D defined of non-PET and PET subjects respectively, who were 60 years and above. 3D CT (Accuitomo; Morita, Kyoto, Japan) was performed on all subjects in the sitting position. The ET lumen from the ET pharyngeal orifice to 15 mm was analyzed. RESULTS: No significant difference in the ET lumen near the pharyngeal orifice was found between Group A and C; however, there was a significant difference in the ET at points lateral to the pharyngeal orifice. The ET lumen was significantly larger at the site close to the pharyngeal orifice in Group B as compared to that of Group A. For the two groups of PET classified according to the size of the pharyngeal orifice and area close to the isthmus, age was only significantly different between two groups of pharyngeal orifice. On the contrary, sonotumometry and Ohta method were significantly different between the two groups of the area close to the isthmus. CONCLUSION: The lumen of the ET is enlarged in both PET and aging. However, the responsible site was found to be different. While the enlargement of the ET lumen in 60 years and above subjects without PET mainly occurred near the pharyngeal orifice of the ET, it was near the isthmus in under 60 years PET patients. Further study of possible clinical implications of these findings as well as treatment strategy are required.

External Ear Diseases: A Comprehensive Review of the Pathologies With Neuroradiological Considerations.

The peripheral auditory system is subdivided into 3 compartments: the external, middle, and inner ear. Historically, the middle and inner ear have garnered more attention in the imaging literature, due to their intricate anatomy and complexity of pathologies. The external ear, however, has attained less recognition given its relatively straightforward anatomy and convenience of direct visual examination. The continued advancement in computed tomography and magnetic resonance imaging has expanded the role of radiology in the evaluation of the external ear lesions. The purpose of this article is to offer a comprehensive review of external ear pathologies, including congenital, inflammatory, infectious, traumatic, neoplastic, and rare disease entities and their imaging findings.

Fibroepithelial Polyp of the External Auditory Canal in a 2-Year-Old Child.

Here, we report a unique case in which a fibroepithelial polyp was found in the cartilaginous part of the external auditory canal of a 2-year-old child. The polyp was successfully treated by excision using an endaural approach and healed without complications. This is the very first report of a fibroepithelial polyp in the external auditory canal in the pediatric population. Although fibroepithelial polyp is an extremely rare diagnosis, it should be considered in the differential diagnosis of a child's external auditory canal polyp.

[Improvement of CT spatial resolution brings about enormous changes in the diagnosis and treatment of otological diseases].

CT examination of temporal bone is of great value in the diagnosis and treatment of otological diseases, and improvement in spatial resolution is an inevitable demand to enhance diagnostic efficiency. In the past 40 years, the spatial resolution of temporal bone CT has been continuously improved, making great contribution to improving the diagnosis and treatment level of otological diseases. The newly reported 10 µm otology CT device has greatly improved the ability to visualize fine structures and occult lesions of temporal bone key area and effectively reduced radiation dose, therefore it is expected to bring new changes to diagnosis and treatment of otological diseases.

Exteriorization of Petrous Bone Cholesteatoma by Endonasal Endoscopic Approach: A Case Report.

A 61-year-old woman presented with diplopia and headache. The patient had a longstanding history of petrous bone cholesteatoma (PBC) on the left side and had undergone multiple surgeries to address it. Computed tomography (CT) revealed a radiolucent lesion with bony destruction in the left petrous apex. Magnetic resonance imaging of the lesion revealed a hypointense area on T1-weighted images and a hyperintense area on T2-weighted and abnormal diffusion-weighted images. A diagnosis of recurrent petrous apex cholesteatoma was made. The patient was treated by exteriorization using an endoscopic endonasal approach. The patient is in remission and doing well. The ideal treatment of PBC is complete excision, though exteriorization using an endoscopic endonasal approach is considered a second option when excision is not possible.

Patulous Eustachian Tube Patients With Respiratory Fluctuation of Tympanic Membrane in Both Sitting and Supine Positions: A Sign of Severity of Disease?

OBJECTIVE: The aim is to report four cases of patulous Eustachian tube (PET) patients with respiratory fluctuation of the tympanic membrane (TM) even in the supine position, and to examine the frequency and characteristics of such patients. PATIENTS: There were 195 ears (99 right ears and 96 left ears) from 146 cases (56 male and 90 female subjects aged 8-88, average 48.0 ±â€Š18.9 yrs) diagnosed with definite PET by diagnostic criteria proposed by Japan Otologic Society (JOS) between January 2017 and December 2019 at Sen-En Rifu Hospital. Patients who presented with respiratory fluctuation of the TM in both the sitting and supine positions were examined. MAIN OUTCOME MEASURES: Clinical patient records, the severity of subjective symptoms (PET handicap inventory-10 [PHI-10]), objective ET function tests (tubo-tympano-aerodynamic graphy [TTAG] and sonotubometry), and sitting three-dimensional computed tomography (3-D CT) were analyzed. RESULTS: Six ears (3.1%) of four cases (2.7%) exhibited respiratory fluctuation of the TM, even in the supine position. In these six ears (four cases), the PHI-10 score ranged from 16 to 36 with three ears exhibiting PHI-10 score equal to or exceeding 26 (in the category of severe handicap). Sitting CT indicated the findings of completely open ET in only two ears. All ears but one were managed by conservative treatment. CONCLUSION: Respiratory fluctuation of the TM in both the sitting and supine positions was observed in 2.7% of the definite PET patients. Surprisingly, such findings can be an indication of neither the subjective nor objective severity of the disease. Therefore, even for PET patients with such findings, surgery should not be immediately proposed, but rather, conservative management should be undertaken first.

A novel missense variant of the GNAI3 gene and recognisable morphological characteristics of the mandibula in ARCND1.

Auriculocondylar syndrome (ARCND) is an autosomal monogenic disorder characterised by external ear abnormalities and micrognathia due to hypoplasia of the mandibular rami, condyle and coronoid process. Genetically, three subtypes of ARCND (ARCND1, ARCND2 and ARCND3) have been reported. To date, five pathogenic variants of GNAI3 have been reported in ARCND1 patients. Here, we report a novel variant of GNAI3 (NM_006496:c.807C>A:p.(Asn269Lys)) in a Japanese girl with micrognathia using trio-based whole exome sequencing analysis. The GNAI3 gene encodes a heterotrimeric guanine nucleotide-binding protein. The novel variant locates the guanine nucleotide-binding site, and the substitution was predicted to interfere with guanine nucleotide-binding by in silico structural analysis. Three-dimensional computer tomography scan, or cephalogram, displayed severely hypoplastic mandibular rami and fusion to the medial and lateral pterygoid plates, which have been recognised in other ARCND1 patients, but have not been described in ARCND2 and ARCND3, suggesting that these may be distinguishable features in ARCND1.

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.

Usage Patterns of CT and MRI in the Evaluation of Otologic Disease.

OBJECTIVE: To evaluate the current trends and usage patterns of radiographic imaging for otologic disease by specialty, length of practice, practice setting, geographic region, and pediatric volume. STUDY DESIGN: Cross-sectional study. SETTING: Survey of physicians. SUBJECTS: General Otolaryngologists and Otologists/Neurotologists (O/N) of the American Academy of Otolaryngology - Head and Neck Surgery (AAO-HNS). METHODS AND OUTCOME MEASURES: An electronic questionnaire was distributed to AAO-HNS members. Respondents were separated into groups by specialty, length of practice, practice setting, region, and pediatric exposure. Chi-square tests were performed for the determination of significance. RESULTS: The survey was sent to 5,168 members of AAO-HNS. The response rate was 10.6% (n = 546) and 18.1% for only O/N (n = 143). Most respondents were generalists (74%), in practice >20 years (51%), with a primarily adult practice (95%). O/N were more often academics (44 versus 17% combined, 40% private; p < 0.001) and saw fewer children (80 fewer than 25%; p < 0.001). Compared with generalists, O/N were more likely to respond with more frequent and earlier magnetic resonance imaging (MRI) utilization in the workup of the majority of otologic diseases. Significant differences in usage patterns for various conditions were demonstrated across all categories, but specialty training was the most common. Generalists (34 versus 12% of O/N; p < 0.001), physicians practicing >20 years (32 versus 18% of < 5 yrs; p = 0.006), and private practice physicians (34 versus 14-20% of others; p < 0.001) relied more heavily on the radiology report to interpret MRI scans. CONCLUSION: Subspecialty training seems to be the main variable correlating with significant differences in the use of MRI and computed tomography imaging in patients with otologic disease.

Morphologic measurements of 3D Eustachian tube model and their diagnostic value regarding Eustachian tube dysfunction - A cross-sectional observational study.

PURPOSE: To investigate the diagnostic value of three-dimensional morphologic measurements of the Eustachian tube on computed tomography in Eustachian tube dysfunction. METHOD: This prospective cross-sectional observational study includes forty patients with unilateral Eustachian tube dysfunction. The clinical diagnosis is verified using the Eustachian tube score - 7 and the Eustachian tube dysfunction questionnaire - 7. Computed tomography scans of the temporal bone are acquired while performing a Valsalva manoeuvre to improve the visualization of the air-filled Eustachian tube lumen. The Eustachian tubes are delineated on curved planar reconstructions, and three-dimensional models are constructed. Seven morphological parameters are measured for each Eustachian tube: the cross-sectional size of the tympanic and pharyngeal orifice; the visualization length; the inclination angles, and the curvature angles. Morphological measurements and Eustachian tube scores are correlated. RESULTS: The mean value of the visualization length of the complete Eustachian tube and in its bony segment is significantly higher in healthy sides than in pathological sides (p = 0.034 and p = 0.029, respectively). There is a significant correlation between the Eustachian tube score - 7 and the cross-sectional size of the tympanic orifice (rP = 0.361; p = 0.022). The Eustachian tube score - 7 correlates significantly with the visualization length of complete Eustachian tube (rP = 0.436; p = 0.005) and its bony segment (rS = 0.598; p < 0.0001), respectively. CONCLUSIONS: The cross-sectional size of the tympanic orifice may be a specific imaging feature indicating the obstructive Eustachian tube. However, 3D morphologic measurements of the Eustachian tube are insufficient to yield useful data about its function.

The use of near infrared fluorescence imaging with indocyanine green for vascular visualization in caudal auricular flaps in two cats.

OBJECTIVES: To describe the use of near infrared fluorescence (NIRF) imaging with indocyanine green (ICG) for vascular visualization in two caudal auricular axial pattern flaps (APF). ANIMALS: Two client-owned cats with upper eyelid masses. STUDY DESIGN: Clinical case report. METHODS: Wide surgical excision with enucleation was performed by using a caudal auricular APF for closure. Flap margins and perforating artery location were approximated with anatomical landmarks. The caudal auricular artery origin was then visualized percutaneously by using an exoscope with NIRF camera and light source after a single 2.5-mg dose of IV ICG. Margins were adjusted as required. The flaps were routinely elevated with continued intraoperative visualization of the artery and rotated to complete closure. RESULTS: After IV ICG administration, fluorescence was initially visualized after 15 to 18 seconds and remained visible for up to 26 minutes. The achieved visualization led to flap margin adjustments in cat 1. Both cats recovered with minimal flap congestion, excellent hair regrowth, and no long-term complications (>186 days). Cat 1 experienced 100% flap survival. Cat 2 experienced 10% partial thickness flap necrosis, but revision was not required, and the flap was healed at recheck 85 days postoperatively. CONCLUSION: The use of ICG for APF vessel visualization prior to and during flap elevation resulted in transcutaneous visualization of the perforating vessel and improved awareness of vessel location intraoperatively. These two cats experienced excellent flap survival without major complications. This report highlights the potential benefits of ICG NIRF in APF for animals undergoing reconstructive surgery.

Endolymphatic hydrops mimicking obstructive Eustachian tube dysfunction: preliminary experience and literature review.

PURPOSE: Aural fullness is a common symptom of middle ear diseases, most importantly Eustachian tube dysfunction (ETD). Yet, aural fullness may also be caused by inner ear disorders, such as hydropic ear diseases. Here, we report our experience with endolymphatic hydrops (EH) mimicking ETD. Furthermore, we review the literature related to (i) EH as a differential diagnosis of symptoms suggesting ETD and (ii) the pathophysiology and treatment of aural fullness due to inner ear disorders. METHODS: We retrospectively included adult patients with aural fullness as chief complaint and radiographically diagnosed EH. Hearing and Eustachian tube function were assessed using audiometry, tympanometry, and tubomanometry. Primarily suspected ETD was treated by balloon dilatation of the Eustachian tube (BDET). The endolymphatic space of the inner ear was imaged using gadolinium-enhanced MRI (Gd-MRI) including a 3D-real inversion-recovery sequence after intravenous gadolinium administration. RESULTS: We report three affected ears of two patients (two females, age 42 and age 51) with aural fullness as chief complaint. Audiometry of main speech frequencies was normal in all affected ears. In one ear, there was a type A tympanogram and in two ears, there was a type B tympanogram. In both patients, medical treatment for ETD and BDET were unsuccessful. Gd-MRI of the inner ears revealed cochlear EH in 3/3 ears affected by aural fullness, but not in the unaffected ear. CONCLUSION: EH may underlay cases with aural fullness and could in these cases explain unsuccessful treatment for ETD. As ETD is often treated by invasive procedures, distinguishing ETD from EH as the underlying cause of aural fullness is important. Our findings raise the question whether Gd-MRI to rule out EH is indicated in patients with unexplained aural fullness, in particular after unsuccessful interventional treatment for ETD.