Pediatric Temporal Bone

Transcription

1 Pediatric Temporal Bone Suresh K. Mukherji, MD, FACR Professor and Chief of Neuroradiology Professor of Radiology, Otolaryngology Head Neck Surgery, Radiation Oncology and Periodontics & Oral Medicine University of Michigan Health System Imaging Techniquee CT Multidetector CT ( rows) Axial CT: 0.625mm thick Direct axial (parallel to IOML) Coronal reformats Magnify both side to 9cm FOV prior to filming

2 Imaging Techniquee MR Full course of CN VIII Slice thickness 3mm (3T: 2mm) Pre-contrast T1W Post-contrast t t axial and coronal Axial T2W Include T2W of brain (MS) T2 DRIVE.29/.29/.29 (Isovoxel) Parallel Imaging

3 EAC Atresia

4 Bony Atresia Membranous Atresia

5 EAC Stenosis EAC Atresia

6 Applied Embryology EAC: 1st Branchial Groove Middle Ear Cavity: 1st Branchial Pouch Ossicle 1st arch: malleus head, short process incus 2nd arch: manubrium of malleus long process incus stapes-head, neck crura, portion of footplate EAC Atresia

7 Ossicular Malformations Anomalous Course of the Facial Nerve

8 Congenital Cholesteatoma Embryonic rest of epithelial tissue No history of TM perforation No history of middle ear infection Imaging Findings: Focal mass medial to the ossicles May be indistinguishable from acquired cholesteatoma Amiysys

9 Oval Window Atresia

10 Oval Window Atresia Inner Ear Malformations Membranous & Osseous Labyrinth (CT/MR+) Complete Labyrinthine Aplasia (Michel) Cochlear Anomalies Aplasia Hypoplasia Incomplete partition (Mondini) Common cavity

11 Complete Labyrinthine Aplasia (Michel) Courtesy: Doug Phillips, M.D. Obliterative Labyrinthitis (Labyrinthitis Ossificans) Schulnecht HF. Pathology of the Ear, 2nd ed.

12 Labyrinthitis Ossificans Michel s Anomaly Inner Ear Malformations Membranous & Osseous Labyrinth (CT/MR+) Complete Labyrinthine Aplasia (Michel) Cochlear Anomalies Aplasia Common cavity Hypoplasia Incomplete partition (Mondini)

13 Cochlear Aplasia/Common Cavity Inner Ear Malformations Membranous & Osseous Labyrinth (CT/MR+) Complete Labyrinthine Aplasia (Michel) Cochlear Anomalies Aplasia Common cavity Hypoplasia Incomplete partition (Mondini)

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15 Inner Ear Malformations Membranous & Osseous Labyrinth (CT/MR+) Complete Labyrinthine Aplasia (Michel) Cochlear Anomalies Aplasia Common cavity Hypoplasia Incomplete partition (Mondini) Mondini Malformation

16 Incomplete Partition (Mondini) Large Vestibular Aqueduct Syndrome Large Vestibular Aqueduct Syndrome LVAS

17 Vestibular Aqueduct Lo et al. AJNR 1997;18: LVAS

18 Pendred Syndrome Initially described in 1896 SNHL + def in iodine organification Thyroid goiter 10% hereditary deafness SLC26A4 gene mutation SLC26Aa also associated with isolayed LVAS Imaging Findings: LVA + modiolar deficiency Branchial-Oto-Renal Syndrome Tapered Cochlea Normal BOR

19 Branchial-Oto-Renal Syndrome Hypoplasia of Middle and Apical Turns Normal BOR Branchial-Oto-Renal Syndrome Sensorineural or mixed HL Inner ear malformations Renal anomalies Branchial cleft anomalies External ear anomalies ETA1 gene mutation Autosomal dominant Imaging g Findings: COCHLEA Funnel-shaped basal turn Hypoplasia middle and apical turns

20 Semicircular Canal Dysplasia/Aplasia Semicircular Canal Aplasia Lateral Semicircular Canal Aplasia Normal

21 Lateral Semicircular Canal Dyaplasia Dysplasia Normal Superior Semicircular Canal Aplasia Aplasia Normal

22 Posterior Semicircular Canal Aplasia Aplasia Normal Coloboma Heart disease CHARGE Atresia choana Retarded growth/development Genital hypoplasia Ear anomalies CHD7 gene mutation Imaging Findings: SCC anomalies (bilateral) l) Cochlear nerve hypoplasia

23 CHARGE SCC Aplasia: Bilateral

24 Vestibular-Cochlear Nerve Cochlear Nerve Canal Stenosis Gusher

25 IAC Stenosis

26 Cochlear Aplasia/Common Cavity

27 X-Linked Mixed Hearing Loss Phelps Anomaly DFN3 Gusher X-chromosome POU3FA gene mutation Syndromic & non-syndromic Imaging: Bulbous IAC Enalarged cochlear canal Absent modiolus X-Linked Mixed Hearing Loss g Phelps Anomaly, DFN3

28 Summary External Auditory Canal Middle Ear Cavity Inner Ear SCCA Dysplasia: CHARGE LVAS: Pendred Syndrome Internal Auditory Canal Dilated IAC with absent Fundus: x-linked hearing loss