378 lines
36 KiB
Markdown
378 lines
36 KiB
Markdown
---
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title: "Sensorineural Hearing Loss in Child"
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docid: "08c895da-f2aa-4076-abf0-af9aca1677cd"
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authors:
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- key: "d19354f3-7ff2-495a-ad3f-064122e45602"
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value: "Bernadette L. Koch, MD"
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breadcrumbs:
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-
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name: "Head and Neck"
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slug: "head-and-neck"
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treeNodeId: "ed24ed8c-5d57-4629-879b-447b82d2973d"
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-
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name: "Differential Diagnosis"
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slug: "differential-diagnosis"
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treeNodeId: "40d68862-8975-4dde-ac2b-ebc43ab0fb5c"
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-
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name: "CPA-IAC and Posterior Fossa"
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slug: "cpa-iac-and-posterior-fossa"
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treeNodeId: "c590eedb-4a3b-4158-a04f-ad880564c992"
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-
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name: "Clinically Based Differentials"
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slug: "clinically-based-differentials"
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treeNodeId: "55dd15ac-e67d-48dd-8134-f52884dab28b"
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-
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name: "Sensorineural Hearing Loss in Child"
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slug: "sensorineural-hearing-loss-in-child"
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treeNodeId: null
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category: "Head and Neck"
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documentVersionId: "89f04762-2cc9-4c62-aea2-256ed544510c"
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imageCount: 44
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lastUpdated: "07/24/18"
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pageDescription: "Sensorineural Hearing Loss in Child"
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pageKeywords: "Head and Neck, Differential Diagnosis, CPA-IAC and Posterior Fossa, Clinically Based Differentials, Sensorineural Hearing Loss in Child"
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pageTitle: "Sensorineural Hearing Loss in Child | STATdx"
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enhancedTitle: "Sensorineural Hearing Loss in Child"
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type: "DDX"
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references: true
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breadcrumbs:
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- "Head and Neck"
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- "Differential Diagnosis"
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- "CPA-IAC and Posterior Fossa"
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- "Clinically Based Differentials"
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- "Sensorineural Hearing Loss in Child"
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---
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# ESSENTIAL INFORMATION
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- ## Key Differential Diagnosis Issues
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- History is important
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- **Congenital sensorineural hearing loss (SNHL)**
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- Failed newborn screening hearing test
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- Look for inner ear anomalies with CT &/or MR
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- **Fluctuating or "cascading" SNHL**in child (without history of meningitis)
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- Look for large vestibular aqueduct (LVA) ± cochlear malformation & modiolar deficiency on CT
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- Look for large endolymphatic sac/duct ± cochlear malformation & modiolar deficiency on MR
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- **Congenital unilateral SNHL**
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- Look for cochlear nerve & cochlear nerve canal (CNC) hypoplasia/aplasia
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- **Trauma**
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- Look for fracture involving inner ear structures ± pneumolabyrinth on CT
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- **Genetic****disorders with common imaging findings**
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- CHARGE, trisomy 21, Waardenburg, or Apert syndrome: Look for semicircular canal (SCC) malformation
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- Pendred syndrome: Look for LVA
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- Biallelic SLC26A4 mutations
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- **Prior****meningitis**
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- CT: Look for labyrinthine ossification
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- T1 C+ MR: Labyrinthine enhancement during meningitis (acute phase)
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- T2 MR: Normal high intensity replaced with low-intensity (fibrosis or ossification) membranous labyrinth
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- Best imaging tool
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- Thin-section T-bone CT for congenital inner ear anomalies & labyrinthine ossificans
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- High-resolution T2 MR for large endolymphatic sac, cochlear malformation; cochlear nerve aplasia/hypoplasia
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- C+ MR best for schwannoma, other tumors, acute labyrinthitis, & autoimmune labyrinthitis (delayed enhancement)
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- ## Helpful Clues for Common Diagnoses
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- **Large Endolymphatic Sac Anomaly (IP-****II****)**
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- Most common congenital anomaly of inner ear found by imaging
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- Axial CT: Vestibular aqueduct (VA) ≥ 2 mm at operculum or ≥ 1 mm at midpoint
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- Associated with incomplete cochlear partition type II (IP-II), modiolar deficiency, vestibule, &/or SCC malformation
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- Additional prognostic information
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- **Avoid contact sports** or other activities that may lead to head trauma
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- Genetic testing for**SLC26A4 mutation** recommended
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- Up to 40% of all patients with LVA & IP-II will have pendrin gene mutation: Pendred syndrome (with thyroid organification defect ± goiter) or LVA
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- **T-Bone Fractures**
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- Thin-section T-bone CT (0.625-1 mm)
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- Transverse, longitudinal, or complex fractures may cross inner ear structures, ± pneumolabyrinth
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- Otic capsule violating vs. otic capsule sparing
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- **Semicircular Canal Malformation**
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- Spectrum of abnormalities: **≥ 1**SCC is malformed, hypoplastic, or aplastic
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- Unilateral or bilateral (e.g., syndromic cases)
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- Most common is short, dilated lateral SCC & vestibule forming single cavity or with small bone island
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- ± cochlear malformation, oval window atresia, &/or ossicular anomalies
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- **CHARGE** syndrome
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- **Bilatera****l****hypoplasia or****absence of all SCCs**
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- Associated anomalies: Small vestibule, absent cochlear nerve aperture ("isolated cochlea"), oval window atresia (± overlying tympanic segment of CNVII), ± choanal atresia, ± coloboma
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- Lateral SCC last to form embryologically; anomalies most frequently affect lateral SCC
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- **Except** if obliterated by labyrinthine ossificans or malformed in Waardenburg, branchiootorenal, & Alagille syndromes
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- **Labyrinthine Ossificans**
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- Synonyms: Labyrinthitis ossificans, labyrinthine ossification, chronic labyrinthitis, ossifying labyrinthitis
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- Acute inflammatory response → fibrous & then osseous replacement of membranous labyrinth; weeks or years
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- May involve cochlea ± vestibule ± SCCs
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- **Bilateral in meningogenic** form (meningitis) & in hematogenic form (blood-borne infections)
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- **Unilateral in tympanogenic** form (middle ear infection)
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- T-bone CT: High-attenuation bone deposition in formerly fluid-filled membranous labyrinth
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- Areas of ossification crucial to identify when planning cochlear implantation
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- T2 MR: Focal or diffuse low intensity replaces high-intensity fluid, with apparent "enlargement" of modiolus if cochlea is involved
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- T1 C+ MR: Enhancement of involved membranous labyrinth structures in early stage, may persist into ossifying stages
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- ## Helpful Clues for Less Common Diagnoses
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- **Labyrinthitis**
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- Sudden onset of SNHL, vertigo, &/or tinnitus
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- Viral disease: Imaging usually not indicated
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- Bacterial, posttraumatic, or autoimmune causes
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- Subacute inflammation of fluid-filled inner ear structures
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- T-bone CT: Normal in early phases, may progress to labyrinthine ossificans
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- T2 MR: Low intensity replaces normal high-intensity fluid signal within membranous labyrinth structures
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- T1 C+ MR: Mild to moderate enhancement
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- Enhancement may persist after symptoms resolve
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- **Cochlear Nerve & Cochlear Nerve Canal Aplasia-Hypoplasia**
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- CT: Small IAC & CNC
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- MR: Fluid in CNC completely or partially replaced by low-signal bone
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- Cochlear nerve diminutive or absent (if CNC aplasia)
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- **Cystic****C****ochleovestibular Malformation (IP-I)**
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- Cystic, featureless cochlea + dilated vestibule & horizontal SCC
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- Cochlea: Absent internal septation & absent modiolus (IP-1), cochlea & vestibule form bilobed cyst
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- Vestibule: Dilated, large, communicates with cochlea
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- SCC: Dilated horizontal + vestibule → common cavity
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- IAC: Small or dilated, defective fundus
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- VA: Usually normal
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- **C****PA-IAC****Lipoma**
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- Congenital fatty lesion of CPA ± IAC ± inner ear
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- Caveat: If T1 C+ MR without fat saturation, may be mistaken for vestibular schwannoma
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- ## Helpful Clues for Rare Diagnoses
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- **Vestibular Schwannoma**
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- Enhancing lesion in IAC or ice cream on cone-shaped mass aligned with CPA-IAC
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- Hypointense T2WI MR
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- **I****ntralabyrinthine****Schwannoma**
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- Rare in children
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- **Intracochlear**: Schwannoma within cochlea
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- **Intravestibular**: Schwannoma within vestibule
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- **Vestibulocochlear**: Involves both vestibule & cochlea
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- **Transmodiolar**: Crosses modiolus; cochlea to IAC fundus
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- **Transmacular**: Crosses from vestibule into IAC fundus
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- **Transotic**: Crosses entire inner ear from IAC fundus to middle ear
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- **F****acial Nerve****Schwannoma in CPA-IAC**
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- Rare in children
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- SNHL with associated facial neuropathy
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- Enhancing, well-circumscribed mass in CPA-IAC; extends into labyrinthine segment of CNVII
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- Involvement of inner ear is secondary finding
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- **Common Cavity Malformation**
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- Featureless common cavity represents rudimentary cochlea, vestibule, & lateral SCC
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- Variably sized common cavity
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- Posterior & superior SCC: Absent, normal, or malformed
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- IAC: Often small with defective fundus ± anomalous course & small or absent CNVIII components
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- Middle ear space & ossicles: Normal or anomalous stapes & stenotic oval window
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- VA: Normal or absent
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- **Cochlear Aplasia**
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- Absent cochlea with variable deformity of vestibule & SCCs
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- Absent/flattened cochlear promontory helps differentiate from labyrinthine ossificans
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- Absent CNC & nerve
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- Hypoplastic IAC
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- Normal VA & normal-sized middle ear cavity
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- Normal or malformed stapes
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- **Labyrinthine Aplasia**
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- **Absent cochlea, vestibule**, &**SCCs**
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- Absent/flattened cochlear promontory
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- IAC aplasia/hypoplasia
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- Absent vestibular & cochlear nerves
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- Normal or malformed ossicles/middle ear
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- Normal or absent carotid canal
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- Old synonym: Michel anomaly
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## References
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# Selected References
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1. [Conte G et al: MR Imaging in Sudden Sensorineural Hearing Loss. Time to Talk. AJNR Am J Neuroradiol. ePub, 2017](http://www.ncbi.nlm.nih.gov/pubmed/?term=28546251%5Bpmid%5D)
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1. [Johnson K et al: High-frequency sensorineural hearing loss in children. Laryngoscope. 126(5):1236-40, 2016](http://www.ncbi.nlm.nih.gov/pubmed/?term=26266337%5Bpmid%5D)
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1. [Shupak A et al: Primary solitary intralabyrinthine schwannoma: A report of 7 cases and a review of the literature. Ear Nose Throat J. 95(12):481-491, 2016](http://www.ncbi.nlm.nih.gov/pubmed/?term=27929596%5Bpmid%5D)
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1. [Prosser JD et al: Diagnostic evaluation of children with sensorineural hearing loss. Otolaryngol Clin North Am. 48(6):975-82, 2015](http://www.ncbi.nlm.nih.gov/pubmed/?term=26429334%5Bpmid%5D)
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1. [Kenna MA et al: Temporal bone abnormalities in children with GJB2 mutations. Laryngoscope. 121(3):630-5, 2011](http://www.ncbi.nlm.nih.gov/pubmed/?term=21298644%5Bpmid%5D)
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1. [Ozgen B et al: Comparison of 45 degrees oblique reformats with axial reformats in CT evaluation of the vestibular aqueduct. AJNR Am J Neuroradiol. 29(1):30-4, 2008](http://www.ncbi.nlm.nih.gov/pubmed/?term=17947373%5Bpmid%5D)
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1. [Vijayasekaran S et al: When is the vestibular aqueduct enlarged? A statistical analysis of the normative distribution of vestibular aqueduct size. AJNR Am J Neuroradiol. 28(6):1133-8, 2007](http://www.ncbi.nlm.nih.gov/pubmed/?term=17569973%5Bpmid%5D)
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1. [Sennaroglu L et al: A new classification for cochleovestibular malformations. Laryngoscope. 112:2230-41, 2002](http://www.ncbi.nlm.nih.gov/pubmed/?term=12461346%5Bpmid%5D)
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## Images
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### Selected Images
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**Large Endolymphatic Sac Anomaly (IP-II)**
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*Axial bone CT in an 8-year-old child with severe bilateral sensorineural hearing loss (SNHL) shows incomplete partitioning between the middle and apical turns of the left cochlea <img src='img/arrows/WS.png'/>, typical of IP-II morphology.*
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**Large Endolymphatic Sac Anomaly (IP-II)**
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*Axial bone CT in an 8-year-old child with severe bilateral sensorineural hearing loss (SNHL) shows incomplete partitioning between the middle and apical turns of the left cochlea <img src='img/arrows/WS.png'/>, typical of IP-II morphology.*
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**Large Endolymphatic Sac Anomaly (IP-II)**
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*Axial bone CT in the same patient shows a markedly enlarged left vestibular aqueduct <img src='img/arrows/WS.png'/>, much larger than 2 mm at the operculum.*
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**Large Endolymphatic Sac Anomaly (IP-II)**
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*Axial FIESTA image in a 3 year old with SNHL shows bilateral enlargement of the endolymphatic sacs <img src='img/arrows/WS.png'/>, incomplete cochlear partitioning <img src='img/arrows/WO.png'/>, and mildly dysmorphic vestibules <img src='img/arrows/WC.png'/>. SCL26A4 mutation/Pendred syndrome was found negative.*
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**T-Bone Fractures**
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*Axial bone CT in a 14 year old involved in a dirt bike accident reveals a horizontal, otic capsule violating right temporal bone fracture crossing the vestibule <img src='img/arrows/WS.png'/>. Notice air in the vestibule and cochlea <img src='img/arrows/WO.png'/> as well as multiple skull base and orbital fractures <img src='img/arrows/WC.png'/>.*
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**Semicircular Canal Malformation**
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*Axial bone CT in a 6-year-old girl demonstrates a short, dilated lateral semicircular canal (SCC) forming a single cavity <img src='img/arrows/BS.png'/> with the vestibule <img src='img/arrows/BO.png'/>, a common type of SCC anlage malformation.*
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**Semicircular Canal Malformation**
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*Axial bone CT in a 3-year-old child with a history of bilateral choanal atresia and hearing loss demonstrates diminutive vestibules <img src='img/arrows/WS.png'/> and absence of the SCCs bilaterally, which is the characteristic appearance of the labyrinth in children with CHARGE syndrome.*
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**Semicircular Canal Malformation**
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*Axial bone CT in a child with Alagille syndrome shows a relatively normal caliber posterior limb of the left superior SCC <img src='img/arrows/WS.png'/>, aplasia of the anterior limb of the superior SCC <img src='img/arrows/WO.png'/>, and aplasia of the posterior SCC <img src='img/arrows/WC.png'/>. In the presence of a normal lateral SCC, these findings are typical of Alagille syndrome.*
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**Labyrinthine Ossificans**
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*Axial bone CT in a patient with prior meningitis and subsequent rapid onset hearing loss shows near complete osseous replacement of the posterior and lateral aspects of the lateral SSCs <img src='img/arrows/WS.png'/> and the left cochlea <img src='img/arrows/WO.png'/>.*
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**Labyrinthine Ossificans**
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*Axial high-resolution CISS MR in a patient with prior meningitis and known partial labyrinthine ossification shows lack of normal T2 hyperintensity in the left membranous <img src='img/arrows/WS.png'/> labyrinth and decreased T2 hyperintensity in the right. The right cochlea <img src='img/arrows/WO.png'/> and vestibule <img src='img/arrows/WC.png'/> are barely visible.*
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**Labyrinthine Ossificans**
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*Axial T1 C+ MR in the same patient shows mild, patchy abnormal enhancement of the bilateral cochlea <img src='img/arrows/WS.png'/> and vestibule <img src='img/arrows/WO.png'/>.*
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**Labyrinthitis**
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*Axial T2 FS MR shows corresponding loss of hyperintense T2 signal in the cochlea <img src='img/arrows/WS.png'/>, vestibule <img src='img/arrows/WC.png'/>, and IAC <img src='img/arrows/WO.png'/>.*
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**Labyrinthitis**
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*Axial T1 C+ FS MR shows abnormal contrast enhancement in the middle ear, mastoid, cochlea <img src='img/arrows/WS.png'/>, vestibule <img src='img/arrows/WC.png'/>, and IAC <img src='img/arrows/WO.png'/>, secondary to actinomycosis labyrinthitis.*
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**Cochlear Nerve & Cochlear Nerve Canal Aplasia-Hypoplasia**
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*Axial bone CT in a 3-year-old girl with unilateral SNHL who failed her newborn hearing test shows an absent cochlear nerve canal <img src='img/arrows/WS.png'/>, sometimes referred to as an "isolated" or "detached" cochlea.*
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**Cochlear Nerve & Cochlear Nerve Canal Aplasia-Hypoplasia**
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*Sagittal oblique T2 MR at the level of the left IAC clearly shows a normal-appearing facial nerve <img src='img/arrows/WS.png'/>, superior/inferior vestibular nerve complex <img src='img/arrows/WO.png'/>, and diminutive left cochlear nerve <img src='img/arrows/WC.png'/>.*
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**Cochlear Nerve & Cochlear Nerve Canal Aplasia-Hypoplasia**
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*Axial high-resolution T2 MR shows absence of the definable right cochlear nerve <img src='img/arrows/WS.png'/> within the right IAC, and lack of a cochlear nerve canal and hypoplasia of the right modiolus <img src='img/arrows/WO.png'/>.*
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**Cochlear Nerve & Cochlear Nerve Canal Aplasia-Hypoplasia**
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*Sagittal oblique T2 MR in the same child shows nonvisualization of the right cochlear nerve <img src='img/arrows/WS.png'/>, which should normally be at least as large as the facial nerve <img src='img/arrows/WO.png'/> on sagittal oblique images through the IAC.*
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**Cystic Cochleovestibular Malformation (IP-I)**
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*Axial bone CT shows the typical CT appearance of cystic cochleovestibular anomaly. The vestibule is globular <img src='img/arrows/BS.png'/>.*
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**Cystic Cochleovestibular Malformation (IP-I)**
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*Axial bone CT in the same patient reveals a featureless cochlea <img src='img/arrows/BS.png'/> without a definable modiolus, also termed an IP-I anomaly.*
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**CPA-IAC Lipoma**
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*Axial NECT shows the typical CT appearance of a small lipoma in the left CPA cistern <img src='img/arrows/WS.png'/>. There is low-attenuation focus of CPA lipoma.*
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**CPA-IAC Lipoma**
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*Coronal T1 MR shows a hyperintense lipoma in the left CPA cistern <img src='img/arrows/WS.png'/>.*
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**Vestibular Schwannoma**
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*Axial T1 C+ FS MR in a 2-year-old boy with neurofibromatosis type 2 clearly shows enhancing masses <img src='img/arrows/WS.png'/> within the bilateral IAC, inseparable from the CNVII/CNVIII complexes.*
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**Vestibular Schwannoma**
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*Axial T2WI MR in the same patient demonstrates corresponding hypointense signal within the IAC masses <img src='img/arrows/WS.png'/>, replacing the normal hyperintense T2-signal fluid, typical of small schwannomas.*
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**Intralabyrinthine Schwannoma**
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*Axial T1 C+ FS MR in a 15-year-old girl with unilateral SNHL shows an enhancing intracochlear mass <img src='img/arrows/WS.png'/> in the middle turn of the cochlea. The tumor enlarged over time and was subsequently resected, confirming intracochlear schwannoma.*
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**Common Cavity Malformation**
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*Axial bone CT demonstrates a common cavity anomaly with a cystic structure representing the vestibule, rudimentary cochlear bud, and horizontal semicircular canal <img src='img/arrows/WS.png'/>, with a relatively normal-appearing posterior semicircular canal <img src='img/arrows/WO.png'/>.*
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**Cochlear Aplasia**
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*Axial bone CT in a 1 year old with SNHL demonstrates a small left IAC <img src='img/arrows/WS.png'/> and absence of the left cochlea <img src='img/arrows/WO.png'/>. Notice also the mild associated hypoplasia of the left petrous apex <img src='img/arrows/WC.png'/>.*
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**Labyrinthine Aplasia**
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*Axial bone CT shows that the otic capsule is featureless <img src='img/arrows/WO.png'/> and without definable labyrinthine structures. The lateral wall is flat <img src='img/arrows/WS.png'/>, indicating congenital absence rather than acquired ossificans.*
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### Additional Images
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**Labyrinthine Ossificans**
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*Axial bone CT shows complete osseous replacement of the right cochlea <img src='img/arrows/WS.png'/>. Notice the presence of a normal right cochlear promontory <img src='img/arrows/WC.png'/>, convex laterally, indicating acquired ossification rather than cochlear aplasia.*
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**Labyrinthine Ossificans**
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*Axial high-resolution T2 MR in a 14 year old with a recent dirt bike accident (resulting in bilateral otic capsule fractures) shows decreased hyperintense T2 signal in the right vestibule <img src='img/arrows/WS.png'/> and lateral semicircular canal (SCC) <img src='img/arrows/WO.png'/>, consistent with early fibrous replacement of normal labyrinthine fluid.*
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**Labyrinthine Ossificans**
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*Axial T1 C + FS MR in the same patient depicts abnormal contrast enhancement involving the right cochlea <img src='img/arrows/WS.png'/>, vestibule <img src='img/arrows/WO.png'/>, and lateral SCC <img src='img/arrows/WC.png'/>, which may persist for months in labyrinthine ossificans.*
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**Labyrinthitis**
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*Axial T1 C+ FS MR shows abnormal enhancement of the right cochlea <img src='img/arrows/WS.png'/>, indicative of labyrinthitis in this patient with Cogan syndrome.*
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**Labyrinthitis**
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*Axial T1 C+ FS MR shows abnormal enhancement of the left cochlea <img src='img/arrows/WS.png'/>, indicative of labyrinthitis in this patient with Cogan syndrome.*
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**Facial Nerve Schwannoma in CPA-IAC**
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*Axial T1 C+ MR shows a variant appearance of a heterogeneously enhancing extraaxial mass <img src='img/arrows/WO.png'/> in the right CPA with extension into the porous acusticus of the right IAC <img src='img/arrows/WS.png'/>.*
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**Facial Nerve Schwannoma in CPA-IAC**
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*Coronal T1 C+ MR shows a large heterogeneously enhancing mass in the CPA cistern and proximal IAC <img src='img/arrows/WS.png'/>.*
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**T-Bone Fractures**
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*Axial bone CT shows a transverse otic capsule violating T-bone fracture <img src='img/arrows/WS.png'/> with associated pneumolabyrinth and gas in the vestibule <img src='img/arrows/WO.png'/> and lateral SCC.*
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**Large Endolymphatic Sac Anomaly (IP-II)**
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*Axial bone CT demonstrates enlargement of the left bony vestibular aqueduct <img src='img/arrows/WS.png'/>.*
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**Large Endolymphatic Sac Anomaly (IP-II)**
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*Axial bone CT shows incomplete partitioning of the left cochlea <img src='img/arrows/WS.png'/> in a patient with large vestibular aqueduct.*
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**T-Bone Fractures**
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*Axial bone CT shows longitudinal temporal bone fracture <img src='img/arrows/BS.png'/> with associated pneumolabyrinth <img src='img/arrows/BC.png'/>.*
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**Semicircular Canal Malformation**
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*Axial bone CT shows lack of the normal right cochlear aperture <img src='img/arrows/BS.png'/> and severe hypoplasia of the vestibule and SCCs <img src='img/arrows/BC.png'/> in a patient with CHARGE syndrome.*
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**Labyrinthitis**
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*Axial T1WI C+ FS MR shows abnormal contrast enhancement in the middle ear, mastoid, cochlea <img src='img/arrows/WS.png'/>, vestibule <img src='img/arrows/WC.png'/>, and IAC<img src='img/arrows/WO.png'/> secondary to actinomycosis labyrinthitis.*
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**Cochlear Nerve & Cochlear Nerve Canal Aplasia-Hypoplasia**
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*Axial bone CT reveals hypoplastic right IAC <img src='img/arrows/BS.png'/> related to right cochlear nerve deficiency.*
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**Cochlear Aplasia**
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*Axial bone CT demonstrates a malformed vestibule <img src='img/arrows/WS.png'/> that communicates with a small IAC through a broad gap at the IAC fundus <img src='img/arrows/WO.png'/>. There is no cochlea anterior to the vestibule.*
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**Cochlear Nerve & Cochlear Nerve Canal Aplasia-Hypoplasia**
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*Axial T2WI MR shows a tiny left IAC <img src='img/arrows/WS.png'/> and nonvisualization of the cochlear nerve.*
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**Cochlear Nerve & Cochlear Nerve Canal Aplasia-Hypoplasia**
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*Sagittal oblique T2 MR shows nonvisualization of the cochlear nerve <img src='img/arrows/WS.png'/> in association with a small IAC. CNVIII and CNVII formation in the IAC area provides the stimulus for IAC formation.*
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**Large Endolymphatic Sac Anomaly (IP-II)**
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*Axial high-resolution FSE MR in a child with bilateral hearing loss shows bilateral enlargement of the extraosseous endolymphatic sacs <img src='img/arrows/WS.png'/> and cochlear modiolar deficiency <img src='img/arrows/WO.png'/>.*
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