Caroline Diana Robson MBChB, Presenter: Editor with royalties, Amirsys, Inc Author with royalties, Amirsys, Inc

1) Improve your basic knowledge and skills relevant to assessing the pediatric temporal bone. 2) Apply principles of critical thinking to provide temporal bone reports that are clinically relevant and of use for parental counseling and surgical planning.

Reporting Temporal Bone Studies  Recognize normal variants in pediatric temporal bone: Cartilaginous cochlear cleft,  enlarged vestibular aqueduct mimics, SCC dehiscence mimics, foramen tympanicum, petrous apex marrow variants Congenital External and Middle Ear Problems 1. External auditory canal (EAC): Normal, stenotic (tympanic plate present/hypoplastic) or atretic (tympanic plate absent). If atretic describe atresia plate: bony (thick or thin) vs bony & membranous. Stenosis + opacification and bony erosion = keratosis obturans or cholesteatoma.  2. Mastoid pneumatization: Pneumatization (development) and aeration 3. Middle ear space size (MES):  Normal, hypoplastic or absent; asses morphology; look for opacity in MES 4. Ossicles & tegmen: Normal or abnormal size, shape, orientation or ossicular fusion/fixation. Tegmen integrity 5. Oval & round windows: Normal, atretic or stenotic 6. Facial nerve (CN7) canal size and course: Normal or anomalous course, normal or dehiscent, small or normal size 7. Inner ear anomalies: Inner ear + EAC/middle ear anomalies = syndrome/teratogenic insult 8. Mandibular condyle size/position: Micrognathia = syndromic etiology 9. Vessels: ICA, IJV, emissary veins, MMA 10. Head and neck & brain: Incidental or related findings Congenital Inner EarProblems 1. Vestibular aqueduct/endolymphatic sac & duct: LVA = midpoint measurement > 0.9 mm & opercular measurement >1.9 mm. Flared LVA associated with incomplete partition (IP-II) cochlea &/or deficient modiolus.  2. Cochlea: Shape & size of turns, interscalar septum (ISS) and/or modiolus. 3. Cochlear nerve canal (CNC) & cochlear nerve: Atresia, stenotic or normal CNC. Absent, hypoplastic or normal nerve. 4. IAC & cranial nerves: Normal, wide or stenotic IAC; symmetric or asymmetric. Absent, hypoplastic or normal CN7 & 8 5. Vestibule: Normal, hypoplastic or globular 6. SCC: Absent, hypoplastic, malformed or normal 7. Assess EAC, MES, vessels, HN and brain

http://media.rsna.org/media/abstract/2014/14000643/RC706B sec.pdf

Robson, C, Reporting Temporal Bone Studies.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14000643.html