Final answer:
In the PECARN study, a CT scan is indicated in children over 2 years old under certain conditions such as Glasgow Coma Scale score less than 15 or worsening mental status within two hours of injury. Additional indications include history of loss of consciousness, severe mechanisms of injury, non-frontal scalp hematoma, or signs of a basilar skull fracture.
Step-by-step explanation:
In the PECARN study, a CT (computed tomography) scan is indicated in children over 2 years old under certain conditions. It is indicated when the child has a Glasgow Coma Scale (GCS) score less than 15 at two hours post-injury, or if there is worsening mental status within two hours of injury.
Additionally, a CT scan is also indicated if there is a history of loss of consciousness for greater than five seconds, severe mechanisms of injury (e.g., high-speed motor vehicle collision), non-frontal scalp hematoma (e.g., swelling or bruising on the scalp), or if there are signs of a basilar skull fracture (e.g., raccoon eyes, Battle's sign).