Bertsimas D, et al. - Since the Pediatric Emergency Care Applied Research Network (PECARN) rules are widely used for triage of CT imaging to identify children with minor head trauma who are at very low risk of clinically important traumatic brain injury (ciTBI), researchers investigated whether optimal classification trees (OCTs), which are novel machine-learning classifiers, improve the predictive accuracy of PECARN rules in this cohort study of 42,412 children with head trauma and without severely altered mental status. Study participants who were examined between June 1, 2004, and September 30, 2006, were picked from 25 emergency departments in North America partaking in PECARN. Findings suggested that the new rules can help to reduce the number of unnecessary computed tomographic imaging scans without missing more patients with traumatic brain injury of clinical importance than the PECARN rules if implemented in the electronic health record.