scholarly journals A novel method of identifying inner ear malformation types by pattern recognition in the mid modiolar section

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anandhan Dhanasingh ◽  
Daniel Erpenbeck ◽  
Masoud Zoka Assadi ◽  
Úna Doyle ◽  
Peter Roland ◽  
...  
Keyword(s):  
Inner Ear ◽  
Internal Auditory Canal ◽  
Type I ◽  
Side View ◽  
Outer Contour ◽  
Vestibular Aqueduct ◽  
A Value ◽  
Straight Line ◽  
Line Parallel ◽  
Inner Ear Malformation

AbstractIdentification of the inner ear malformation types from radiographs is a complex process. We hypothesize that each inner ear anatomical type has a uniqueness in its appearance in radiographs. The outer contour of the inner ear was captured from the mid-modiolar section, perpendicular to the oblique-coronal plane, from which the A-value was determined from CT scans with different inner ear anatomical types. The mean A-value of normal anatomy (NA) and enlarged vestibular aqueduct syndrome (EVAS) anatomical types was greater than for Incomplete Partition (IP) type I, II, III and cochlear hypoplasia. The outer contour of the cochlear portion within the mid-modiolar section of NA and EVAS resembles the side view of Aladdin’s lamp; IP type I resembles the side-view of the Sphinx pyramid and type II a Pomeranian dog’s face. The steep spiraling cochlear turns of IP type III resemble an Auger screw tip. Drawing a line parallel to the posterior margin of internal auditory canal (IAC) in axial-view, bisecting the cavity into cochlear and vestibular portions, identifies common-cavity; whereas a cavity that falls under the straight-line leaving no cochlear portion identifies cochlear aplasia. An atlas of the outer contour of seventy-eight inner ears was created for the identification of the inner malformation types precisely.

scholarly journals A novel cochlear measurement that predicts inner-ear malformation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tawfiq Khurayzi ◽  
Fida Almuhawas ◽  
Abdulrahman Alsanosi ◽  
Yassin Abdelsamad ◽  
Úna Doyle ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Inner Ear ◽  
Type I ◽  
Basal Turn ◽  
Type Iii ◽  
A Value ◽  
Inner Ear Malformation ◽  
C Value ◽  
Temporal Bones ◽  
Value Measurement

AbstractThe A-value used in cochlear duct length (CDL) estimation does not take malformed cochleae into consideration. The objective was to determine the A-value reported in the literature, to assess the accuracy of the A-value measurement and to evaluate a novel cochlear measurement in distinguishing malformed cochlea. High resolution Computer Tomography images in the oblique coronal plane/cochlear view of 74 human temporal bones were analyzed. The A-value and novel C-value measurement were evaluated as predictors of inner ear malformation type. The proximity of the facial nerve to the basal turn was evaluated subjectively. 26 publications report on the A-value; but they do not distinguish normal vs. malformed cochleae. The A-values of the normal cochleae compared to the cochleae with cochlear hypoplasia, incomplete partition (IP) type I, -type II, and -type III were significantly different. The A-value does not predict the C-value. The C-values of the normal cochleae compared to the cochleae with IP type I and IP type III were significantly different. The proximity of the facial nerve to the basal turn did not relate to the type of malformation. The A-value is different in normal vs. malformed cochleae. The novel C-value could be used to predict malformed anatomy, although it does not distinguish all malformation types.

scholarly journals Study on the relationship between the pathogenic mutations of SLC26A4 and CT phenotypes of inner ear in patient with sensorineural hearing loss

2019 ◽  
Vol 39 (3) ◽  
Author(s):  
Lihua Wu ◽  
Yunliang Liu ◽  
Jianman Wu ◽  
Sheng Chen ◽  
Shupin Tang ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Ct Scan ◽  
Inner Ear ◽  
Gene Mutations ◽  
Pathogenic Mutation ◽  
Vestibular Aqueduct ◽  
Slc26a4 Gene ◽  
Pathogenic Mutations ◽  
Inner Ear Malformation ◽  
Single Allele

Abstract To investigate the possible association of pathogenic mutations of SLC26A4 and computerized tomography (CT) phenotypes of inner ear, and explore the feasibility of using the method of gene sequence analysis. A total of 155 patients with bilateral hearing loss carrying SLC26A4 gene mutations were further subjected to high-resolution temporal bone CT and thyroid B ultrasound tests. The potential relationship between the pathogenic mutations of gene and the CT phenotypes were analyzed. As a result, 65 patients (41.9%, 65/155) carried SLC26A4 gene mutations, and 27 cases were detected with pathogenic mutations of SLC26A4 where IVS7-2A>G (55.6%, 15/27) was the most common pathogenic mutation. Amongst them, 19 patients carrying bi-allelic SLC26A4 mutations were all confirmed to have inner ear malformation by CT scan including four cases of enlarged vestibular aqueduct (EVA) and 15 cases of Mondini dysplasia (MD). However, there was only one in eight cases of single allele pathogenic mutation who was confirmed to have EVA by CT scan. Further, only one patient with EVA was confirmed to be slightly higher of total T3 than normal by thyroid ultrasound scan and thyroid hormone assays. These findings suggested that CT detection and SLC26A4 gene detection are efficient methods to diagnose EVA, which can complement each other. Also, the bi-allelic pathogenic mutations of SLC26A4 are more likely to induce inner ear malformation than single allele pathogenic mutation.

Duplicated internal auditory canal with inner ear malformation: Case report and literature review

2018 ◽  
Vol 45 (2) ◽  
pp. 351-357 ◽  
Author(s):  
Yoshitaka Takanashi ◽  
Tetsuaki Kawase ◽  
Yasuko Tatewaki ◽  
Jun Suzuki ◽  
Izumi Yahata ◽  
...  
Keyword(s):  
Case Report ◽  
Literature Review ◽  
Inner Ear ◽  
Internal Auditory Canal ◽  
Inner Ear Malformation

Inner-ear malformations as a cause of single-sided deafness

2020 ◽  
Vol 134 (6) ◽  
pp. 509-518
Author(s):  
E Tahir ◽  
M D Bajin ◽  
S Jafarov ◽  
M Ö Yıldırım ◽  
B Ç Çınar ◽  
...  
Keyword(s):  
Inner Ear ◽  
Internal Auditory Canal ◽  
Cochlear Nerve ◽  
Resonance Imaging ◽  
Radiological Findings ◽  
Inner Ear Malformations ◽  
Disease Prognosis ◽  
Inner Ear Malformation ◽  
Ear Malformations ◽  
Single Sided Deafness

AbstractObjectiveTo determine the prevalence and distribution of inner-ear malformations in congenital single-sided deafness cases, as details of malformation type are crucial for disease prognosis and management.MethodsA retrospective study was conducted of 90 patients aged under 16 years with congenital single-sided deafness. Radiological findings were evaluated using computed tomography and magnetic resonance imaging. Inner-ear malformations were identified and cochlear nerve status was determined in affected ears.ResultsOut of 90 ears, 42 (46.7 per cent) were found to have inner-ear malformation. Isolated cochlear aperture stenosis was the most common anomaly (n = 18, 20 per cent), followed by isolated cochlear aperture atresia (n = 11, 12.2 per cent) and cochlear hypoplasia (n = 7, 7.8 per cent). Cochlear nerve deficiency was encountered in 41 ears (45.6 per cent). The internal auditory canal was also stenotic in 49 ears (54.4 per cent).ConclusionInner-ear malformations, especially cochlear aperture anomalies, are involved in the aetiology of single-sided deafness more than expected. The cause of single-sided deafness differs greatly between congenital and adult-onset cases. All children with single-sided deafness should undergo radiological evaluation, as the prognosis and management, as well as the aetiology, may be significantly influenced by inner-ear malformation type.

Enlarged vestibular aqueducts and other inner-ear abnormalities in patients with Down syndrome

2016 ◽  
Vol 131 (4) ◽  
pp. 298-302 ◽  
Author(s):  
C M Clark ◽  
H H Patel ◽  
S G Kanekar ◽  
H Isildak
Keyword(s):  
Computed Tomography ◽  
Hearing Loss ◽  
Down Syndrome ◽  
Sensorineural Hearing Loss ◽  
Inner Ear ◽  
Internal Auditory Canal ◽  
Sensorineural Hearing ◽  
Vestibular Aqueduct ◽  
Computed Tomography Images ◽  
Temporal Bones

AbstractBackground:Histopathological anomalies of inner-ear structures in individuals with Down syndrome have been well documented; however, few studies have examined the radiological features.Methods:A retrospective study was conducted of temporal bone computed tomography images in 38 individuals (75 ears) with Down syndrome to evaluate the prevalence of inner-ear abnormalities and assess vestibular aqueduct widths.Results:Inner-ear anomalies were identified in 20 of the 38 individuals (52.6 per cent). Seven of the 75 temporal bones (9.3 per cent) were found to have higher than previously reported. A dilated internal auditory canal and vestibule were more common among the present study group, while prior studies have demonstrated internal auditory canal stenosis and decreased vestibule size.Conclusion:Down syndrome patients exhibit a high prevalence of dysplastic inner-ear features that confer substantial risk of sensorineural hearing loss. Computed tomography is a useful screening aid to detect inner-ear abnormalities, particularly enlarged vestibular aqueducts, which cause preventable sensorineural hearing loss in this population.

Drilling the posterior wall of the petrous pyramid: a microneurosurgical anatomical study

1993 ◽  
Vol 78 (3) ◽  
pp. 452-455 ◽  
Author(s):  
Mario Ammirati ◽  
Jianya Ma ◽  
Melvin L. Cheatham ◽  
David Maxwell ◽  
Joseph Bloch ◽  
...  
Keyword(s):  
Inner Ear ◽  
Internal Auditory Canal ◽  
Anatomical Study ◽  
Posterior Wall ◽  
Anterior Portion ◽  
Content Type ◽  
Vestibular Aqueduct ◽  
Drilling Technique ◽  
Minimum Depth ◽  
Horizontal Portion

✓ Posterior approaches to the petroclival area requiring extensive drilling of the posterior pyramidal wall have been described in the last 10 years. If hearing is to be preserved, damage to the inner-ear structures must be avoided; however, the fine points of this pyramidal drilling technique have never been reported in detail. A microneurosurgical anatomical study was undertaken in 15 cadavers to determine the relationships between bone landmarks and labyrinthine structures that could be used to give some practical drilling guidelines. Drilling of the posterior pyramidal wall is facilitated on identification of the intersection of the petrous ridge with the most anterior portion of the bone ledge covering the sigmoid sinus (petrosigmoid intersection), the bony operculum of the endolymphatic sac, and the petrous ridge. Drilling may proceed rather safely at a minimum depth of 2.5 mm in an area 0.9 cm anterior and 1 cm inferior to the petrosigmoid intersection and petrous ridge, respectively. From there, identification of the vestibular aqueduct, genu, and horizontal portion is necessary to safely open the posterior wall of the internal auditory canal. The vestibular aqueduct represents the lateral and superior limits of drilling. The bone between these areas may then be safely drilled to a depth of at least 2.5 mm. A microneurosurgical dissection of the posterior pyramidal wall conducted in cadaveric material according to these guidelines did not violate any inner-ear structures.

scholarly journals Incomplete Partition type I: Radiological Evaluation of the Temporal Bone

Acta Medica ◽  
2021 ◽  
pp. 1-9
Author(s):  
Safak Parlak ◽  
Ayca Akgoz Karaosmanoglu ◽  
Sevtap Arslan ◽  
Levent Sennaroglu
Keyword(s):  
Inner Ear ◽  
Temporal Bone ◽  
Correct Diagnosis ◽  
Semicircular Canals ◽  
Type I ◽  
Vestibular Aqueduct ◽  
Endolymphatic Duct ◽  
Incomplete Partition ◽  
Internal Acoustic Canal ◽  
Large Vestibular Aqueduct

Objective: Incomplete partition type I is an uncommon congenital anomaly of the inner ear, characterized by typical cystic cochleovestibular appearance. Incomplete partition type I was firstly defined as cystic cochlea and vestibule without large vestibular aqueduct; however, large vestibular aqueduct and/or enlarged endolymphatic duct could rarely be seen in incomplete partition type I anomaly. Correct diagnosis of the type of cochlear malformation and differentiation of incomplete partition type I is necessary for patient management and surgical approach. Our aim was to document the temporal bone imaging findings in a series of patients with incomplete partition type I. Materials and Methods: CT (n=85) and/or MRI (n=80) examinations of 99 ears in 59 incomplete partition type I patients were retrospectively evaluated. All structures of the otic capsule were retrospectively assessed. The appearances of cochlea and vestibule, vestibular aqueduct/endolymphatic duct, semicircular canals were qualitatively evaluated by an experienced neuroradiologist. The vertical dimension of vestibular aqueduct and/or endolymphatic duct (from the point where the duct arises from the vestibule) was measured on CT/MRI. Anterior-posterior diameter of the internal acoustic canal and the diameter of cochlear aperture were measured on CT. The cochleovestibular nerves were evaluated on sagittal-oblique high T2-weighted imaging. Results: All 99 ears had defective partition with unpartitioned cochlear basal turn and absent interscalar septae, separated but cystic cochlea. The vestibule was enlarged in all ears except one. Semicircular canals were usually dysplastic (92.9%). A total of 35 incomplete partition type I ears (35.3%) had large vestibular aqueduct and/or enlarged endolymphatic duct. Internal acoustic canal was wide in 21% of ears. Cochlear aperture was wide in 5.9% of ears. Cochlear nerve was either hypoplastic or aplastic in about a quarter of incomplete partition type I ears. Conclusion: In up to one-third of incomplete partition type I patients, an associated large vestibular aqueduct /endolymphatic duct could be seen accompanying typical inner ear findings. Although the cochlear nerves are normal in the majority of cases, auditory brainstem implantation may be necessary in certain cases of incomplete partition type I anomaly.

scholarly journals A New Pathogenic Variant in POU3F4 Causing Deafness Due to an Incomplete Partition of the Cochlea Paved the Way for Innovative Surgery

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 613
Author(s):  
Ahmet M. Tekin ◽  
Marco Matulic ◽  
Wim Wuyts ◽  
Masoud Zoka Assadi ◽  
Griet Mertens ◽  
...  
Keyword(s):  
Inner Ear ◽  
Surgical Planning ◽  
Internal Auditory Canal ◽  
Pathogenic Variant ◽  
Liquor Cerebrospinalis ◽  
Clinical Tool ◽  
Inner Ear Malformation ◽  
Cochlear Implant Surgery ◽  
Incomplete Partition ◽  
Genetic Results

Incomplete partition type III (IP-III) is a relatively rare inner ear malformation that has been associated with a POU3F4 gene mutation. The IP-III anomaly is mainly characterized by incomplete separation of the modiolus of the cochlea from the internal auditory canal. We describe a 71-year-old woman with profound sensorineural hearing loss diagnosed with an IP-III of the cochlea that underwent cochlear implantation. Via targeted sequencing with a non-syndromic gene panel, we identified a heterozygous c.934G > C p. (Ala31Pro) pathogenic variant in the POU3F4 gene that has not been reported previously. IP-III of the cochlea is challenging for cochlear implant surgery for two main reasons: liquor cerebrospinalis gusher and electrode misplacement. Surgically, it may be better to opt for a shorter array because it is less likely for misplacement with the electrode in a false route. Secondly, the surgeon has to consider the insertion angles of cochlear access very strictly to avoid misplacement along the inner ear canal. Genetic results in well describes genotype-phenotype correlations are a strong clinical tool and as in this case guided surgical planning and robotic execution.

scholarly journals Diagnostic Value of 3D Segmentation in Understanding the Anatomy of Human Inner Ear Including Malformation Types

2020 ◽  
pp. 014556132090662
Author(s):  
Saad Alenzi ◽  
Anandhan Dhanasingh ◽  
Hani Alanazi ◽  
Abdulrahman Alsanosi ◽  
Abdulrahman Hagr
Keyword(s):  
Inner Ear ◽  
Three Dimensional ◽  
Internal Auditory Canal ◽  
B Value ◽  
Data Sets ◽  
Type Ii ◽  
3D Segmentation ◽  
Training Tool ◽  
A Value ◽  
Human Inner Ear

Objective: To understand the anatomical and dimensional variations of the human inner ear using 3-dimensional (3D) segmentation within the Middle East population. Design: Retrospective study. Setting: King Abdullah Ear Specialist Center (KAESC) Riyadh, Saudi Arabia. Participant: Forty computed tomography (CT) images of patients with sensorineural hearing loss who underwent cochlear implant (CI) were taken for analysis. Main outcome Measures: Three-dimensional images showing the anatomical variations of the inner ear including various pathological conditions, cochlear parameters including basal turn diameter (“A” value), “B” value which is perpendicular to “A” value, cochlear height, length, and width of the internal auditory canal (IAC), intercochlear spacing, and electrode angular insertion depth (AID). Results: Out of 40 CT image data sets, 12 had normal inner-ear anatomy (NA), 4 with enlarged vestibular aqueduct syndrome (EVAS), 8 with only 2 turns of the cochlea (2TL), 7 with incomplete partition (IP) type II, 5 with cochlear hypoplasia, 1 with common cavity, and 3 with abnormal IAC. Taking the NA, EVAS, 2TL, and the IP type II cases altogether, age of the patient had no correlation with the “A” value; however, the “A” value had a linear correlation with the “B” value. The age of the patient had an increasing logarithmic correlation with the IAC length and the intercochlear spacing. The “A” value did not have any meaningful correlation with the cochlear height. Three data sets showed asymmetric inner-ear malformation types on either side of the ears. All these 40 cases were implanted with various CI electrode array variants and the corresponding postoperative plain film X-ray images showing the electrode AID are given separately in figures. Conclusions: Three-dimensional segmentation of the inner ear from the temporal bone CT is a valuable clinical and training tool for surgeons and radiologists especially in difficult cases which will certainly help to understand the overall anatomical and dimensional variations.

Aortic tortuosity index as a predictor of type A aortic dissection

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
F Scalbert ◽  
O Milleron ◽  
M Para ◽  
R Raffoul ◽  
Q Pellenc ◽  
...  
Keyword(s):  
Aortic Dissection ◽  
Type A ◽  
Ct Scans ◽  
Control Group ◽  
Type A Aortic Dissection ◽  
Total Length ◽  
A Value ◽  
Straight Line ◽  
Patients At Risk ◽  
Geometric Length

Abstract Introduction The risk ok type A aortic dissection (AAD) depends on the degree of aortic wall's alteration, which can result in dilatation or tortuosity. The estimate of this risk relies solely on the evaluation of the diameter of the ascending aorta. Purpose The purpose of this study is to evaluate the presence and importance of aortic tortuosity in patients with type A aortic dissection. Method Postoperative CT scans of patients with type A aortic dissection were compared with CT scans from controls matched for gender and age. After 3D reconstruction, total length (actual distance along aortic center line = Ltot) and geometric length (length of a straight line between start and end of the aortic segment = Lgeo) were measured to calculate the tortuosity index (TI = Ltot / Lgeo). Results Ltot, Lgeo and TI from different aortic segments of the AAD group were higher than in the control group. Ltot and TI of the whole aorta (from aortic valve to bifurcation) were greater in patients with type A aortic dissection (527.7±46.1 mm vs. 475.8±39.7, p<0.0001; and 2.05±0.24 vs. 1.98±0.21, p=0.002 respectively). Total length and TI were greater after exclusion of the ascending part, and a value of this TI >1.3 identifies AAD patients with an accuracy of 74.8% (AUC = 0.792, p<0.0001). TI is altered by risk factors for aortic dissection: it increases with hypertension and age but not by tobacco use, and TI decreases in diabetes. Conclusions Type A aortic dissection is associated with longer aorta and increased aortic tortuosity. This index may help recognize patients at risk for type A aortic dissection. Calculation of tortuosity indexes Funding Acknowledgement Type of funding source: None

Sign in / Sign up

Export Citation Format

Share Document