Traumatic brain injury (TBI) is one of the commonest causes of death and disability in childhood. The causes of the injury can be either accidental (e.g., motor vehicle accident, direct blow) or non-accidental head injury (NAHI). Primary brain injury involves the direct consequence of the injury to the brain (e.g., contusion) while secondary injury is the result of brain edema causing other problems such as vascular compromise.
Magnetic resonance spectroscopy (MRS), diffusion-weighted imaging (DWI), and perfusion-weighted imaging (PWI) techniques and their applications in adult head injury have already been reviewed in previous Chapters. 1, 4, 7, and 42. Here the specific applications of new imaging techniques to pediatric brain and spine trauma are reviewed.
Mechanisms of injury in accidental trauma and specific considerations in pediatrics
The pediatric brain differs in many ways from the adult brain in the way in which it responds to and recovers from trauma. The protective calvarium is softer in the first few years of life, resulting in it being easier to fracture. Fracture patterns are also different (Fig. 54.1).
In pediatrics, the relative laxity of ligaments and reduced muscle development make spinal injury, without associated bony injury, more likely. Therefore, all patients with TBI who are requiring ventilatory support for over 48 h in our institution undergo MR of the brain and whole spine to assess for the extent of intracranial injury (with the routine use of DWI and gradient echo imaging to look for evidence of hypoxic brain injury and diffuse axonal injury) together with sagittal imaging of the whole spine (T1, T2 and T2 fat saturated or short TI inversion recovery [STIR] imaging) to look for bony injury and/or spinal cord injury without (conventional) radiological abnormality (SCIWORA) (Fig. 54.2).