Imaging diagnosis of os odontoideum / 实用放射学杂志

ABSTRACT

Objective To investigate the imaging manifestations of os odontoideum and to improve the level of diagnosis and treatment of this disease.Methods Imaging data of 22 patients with os odontoideum were analyzed retrospectively.Results Os odontoideum was divided into round,oval,conical and irregular shapes,with intact cortex and hypertrophy of anterior arch of atlas.Two cases of orthotopic and 20 cases of dystopic os odontoideum were included.There was no displacement of the base of the odontoid process in 7 cases,with anterior displacement in 6 cases and posterior displacement in 9 cases.A widening of anterior atlanto-axial joint space with varying degrees was observed in 14 cases.Thickening of the soft tissue posterior to the odontoid process was showed in 18 cases,spinal canal stenosis in 21 cases,spinal cord degeneration in 11 cases and craniocervical junction malformation in 9 cases.Conclusion Os odontoideum is a well-corticated bone mass,with other related changes,such as hypertrophy of anterior arch of atlas,small posterior arch of atlas,atlantoaxial instablity, spinal stenosis and so on.The imaging features can provide important reference for clinical diagnosis and treatment.