Purpose or Case Report: Delayed phase imaging increases the sensitivity of detection of injuries to the urinary tract and also assists in characterizing solid visceral organ injuries at the expense of doubling the radiation dose to the patient. If institutions can lower the rate of these examinations, the cumulative radiation exposure reduction would be substantial. Here we evaluate the rate of delayed phase imaging in the pediatric trauma population at our Level I trauma center as well as the frequency with which these patients demonstrate an indication on portal venous imaging for delayed phase acquisition. Finally, there are minimal guidelines dictating the appropriateness of delayed imaging in pediatric trauma. We include a review of the literature in order to elucidate appropriate indications and help guide clinicians to make evidenced based decisions.
Methods & Materials: A retrospective chart review was performed analyzing data of pediatric (0-18 years) trauma activations at our institution with a CT chest/abdomen/pelvis, between January 1 2016-January 1 2018. The primary variable analyzed was acqusition of delayed imaging. Indications for delayed imaging on portal venous phase imaging, including solid organ injury, pelvic fracture, and free fluid, were also reviewed. Given the potential for physiologic free fluid in post-pubescent girls, data was also analyzed excluding free fluid as an indication in girls older than 12 years old.
Results: 134 patients met the inclusion criteria. Delayed imaging was acquired in the majority of patients (91%, n=122). There was a near even split for presence/abscence of an indication for delayed imaging on the portal venous phase imaging. There was no statistical correlation with an indication for delayed imaging and the acquisition of delayed imaging (p=0.475). When accounting for each indication independently, there was no statistical correlation between a specific indication and acquisition of delayed imaging.
Conclusions: We found no correlation between indication for delayed-phase imaging and its acquisition in pediatric trauma patients at our Level I trauma center. Delayed phase imaging was obtained in the vast majority of these patients, irrespective of indication. Improving referral education and adoption of a protocol in which delayed imaging is only obtained in pediatric patients with appropriate indications could reduce the effective radiation dose to the pediatric trauma patients at our instition by 25%. Review of the literature corroborates these findings.