title: CT and myelogram findings of os odontoideum.
abstract: We reviewed the findings of CT and myelogram of cases of os odontoideum. The diagnosis was confirmed by conventional tomogram in all these cases. Four cases were further confirmed by trans-oral decompression. Cartilage was found between the os odontoideum and the odontoid process during operation in these 4 cases. Four of them had no history of trauma and 2 of them had an associated anomaly; one was Down's syndrome, and the other was barrel chest and congenital dislocation of hips. CT findings of os odontoideum in these cases were a constriction and/or a gap of bony structure between the os odontoideum and the odontoid process. Myelograms showed spinal stenosis as a result of atlanto-axial dislocation, or anterior extradural compression from overgrown cartilage and posteriorly dislocated tip of shortened odontoid process.
authors.affiliation: Department of Radiology, Veterans General Hospital, Taiwan, Republic of China.
authors.forename: M M
authors.initials: MM
authors.lastname: Teng
authors.forename: H M
authors.initials: HM
authors.lastname: Shoung
authors.forename: C Y
authors.initials: CY
authors.lastname: Chang
authors.forename: W Y
authors.initials: WY
authors.lastname: Guo
authors.forename: C M
authors.initials: CM
authors.lastname: Tiu
authors.forename: T
authors.initials: T
authors.lastname: Chang
mesh_terms: D000293:Adolescent; D000328:Adult; D001268:Atlanto-Axial Joint / Q000000981:diagnostic imaging / Q000293:injuries; D001368:Axis, Cervical Vertebra / Q000000981:diagnostic imaging*; D001270:Cervical Atlas / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D004204:Joint Dislocations / Q000150:complications / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D009192:Myelography; D009809:Odontoid Process / Q000000981:diagnostic imaging* / Q000196:embryology; D013130:Spinal Stenosis / Q000000981:diagnostic imaging / Q000209:etiology; D014057:Tomography, X-Ray Computed