Purpose or Case Report: Pediatric cervical spine trauma, although rare with an incidence of only 1-2%, can have very high morbidity and mortality. The leading causes are motor vehicle collision, sports related injury and child abuse in infants. The incidence of upper cervical spine injury is more common in children than adults due to differences in biomechanics, with the pediatric head size being proportionally larger when compared to adults. Although conventional radiographs remain the standard initial imaging evaluation, CT has become an important modality to detect bony injury and subtle signs of underlying ligamentous injury and hemorrhage (although consideration must be made for the increased radiation exposure). The presence of ligamentous injury, dens synchondrosis fracture, spinal cord evaluation, and spinal cord injury without radiographic abnormality (SCIWORA), meanwhile, are better evaluated with MRI. We will review the normal appearance of the pediatric cervical spine including normal measurements on radiographs and CT, including the importance of the basion-dens interval, powers ratio, and atlanto-occipital distance with illustrations. The normal development of the cervical spine as well as CT and MRI anatomy of cervical spine ligaments will be reviewed with illustrations. Imaging findings of atlanto-occipital and atlanto-axial distraction and pediatric cervical spine fractures including clay shoveler's fracture and dens synchondrosis fractures will be illustrated with CT and MRI. Finally, a review of clinical decision criteria for pediatric cervical spine trauma and imaging approach will be presented. The importance of obtaining MRI in children under 5 years and appropriate use of imaging will also be discussed.

Image 1: Sagittal CT image demonstrates increased basion to dens distance and normal atlanto-dental interval, consistent with atlanto-occipital dissociation.
Image 2: T2-weighted sagittal MR image demonstrates injuries to the tectorial and posterior atlanto-occipital membranes with atlanto-occipital dissociation. There is associated epidural hemorrhage.
Image 3: Sagittal CT reconstruction demonstrates a powers ratio greater than 1, raising suspicion for anterior atlanto-occipital dissociation.
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