The following imaging algorithm for pediatric head and neck injury (this algorithm also contains the algorithm for adult head and neck imaging) is from the National Institute of Health and Care Excellence (NICE). It is from Head injury: Triage, assessment, investigation and early management of head injury in children, young people and adults. NICE guidelines [CG176] Published date: January 2014
Also be sure to review Management of Pediatric Cervical Spine and Spinal Cord Injuries [PubMed Citation] [ Text HTML] [Available as PDF Download from the HTML link]. Neurosurgery. 2013 Mar;72 Suppl 2:205-26.
Please see also Introduction to the Guidelines for the Management of Acute Cervical Spine and Spinal Cord Injuries. [PubMed Citation] [Full Text HTML] [From the previous HTML link you can also download the PDF which is easier to review than the HTML version] Neurosurgery. 2013 Mar;72 Suppl 2:5-16. This citation has a brief readable summary of all the adult and pediatric recommendations.
The above are excellent British Guidelines but The American Guidelines (Introduction to the Guidelines above) would favor high quality CT (if available) over plain radiographs of the cervical spine.
Imaging Algorithm For Adult Head and Neck Injury From NICE Posted on September 3, 2015 by Tom Wade MD.