Although precise comparison among the clinical decision rules is limited by differences in methodology and outcomes, the PECARN criteria remain the most widely validated, particularly for very young children, because of the high sensitivity and strong validation; the PECARN guidelines have been incorporated into the clinical variants for acute minor pediatric head trauma imaging. The PECARN criteria are summarized in Appendix 1. MRI The identification of small bleeds, particularly in the posterior fossa or brainstem, is further increased with hemesensitive techniques such as susceptibility-weighted imaging [2,24-26]. Diffusion-weighted imaging can be helpful in identifying nonhemorrhagic injuries and associated ischemia as well [27]. Standard MRI sequences have a low sensitivity for skull fractures. In recent years, limited rapid brain MRI techniques have been investigated as a means to evaluate pediatric head trauma without the need for sedation. Preliminary data suggest variations of this method may be helpful in following known intracranial hemorrhage documented by CT, but the sensitivity of rapid MRI in lieu of CT remains uncertain [28-31]. Additionally, there is no single uniform definition for rapid brain MRI techniques, and protocols vary among institutions. This is a rapidly evolving area of investigation but, at this time, there is no distinct procedural assignment for fast brain MRI in the ACR lexicon. Ultrasound A few recent studies in children have suggested ultrasound (US) can detect calvarial fractures with a sensitivity close to that of CT [32]. However, even in infants with open fontanelles, in which US imaging of the brain is possible, US lacks sensitivity for small subdural hematomas, particularly in the posterior fossa, as well as other small extra-axial hemorrhages.
Head Trauma Child PCAs. Although precise comparison among the clinical decision rules is limited by differences in methodology and outcomes, the PECARN criteria remain the most widely validated, particularly for very young children, because of the high sensitivity and strong validation; the PECARN guidelines have been incorporated into the clinical variants for acute minor pediatric head trauma imaging. The PECARN criteria are summarized in Appendix 1. MRI The identification of small bleeds, particularly in the posterior fossa or brainstem, is further increased with hemesensitive techniques such as susceptibility-weighted imaging [2,24-26]. Diffusion-weighted imaging can be helpful in identifying nonhemorrhagic injuries and associated ischemia as well [27]. Standard MRI sequences have a low sensitivity for skull fractures. In recent years, limited rapid brain MRI techniques have been investigated as a means to evaluate pediatric head trauma without the need for sedation. Preliminary data suggest variations of this method may be helpful in following known intracranial hemorrhage documented by CT, but the sensitivity of rapid MRI in lieu of CT remains uncertain [28-31]. Additionally, there is no single uniform definition for rapid brain MRI techniques, and protocols vary among institutions. This is a rapidly evolving area of investigation but, at this time, there is no distinct procedural assignment for fast brain MRI in the ACR lexicon. Ultrasound A few recent studies in children have suggested ultrasound (US) can detect calvarial fractures with a sensitivity close to that of CT [32]. However, even in infants with open fontanelles, in which US imaging of the brain is possible, US lacks sensitivity for small subdural hematomas, particularly in the posterior fossa, as well as other small extra-axial hemorrhages.