Rates and clinical impact of discordant X-ray and CT imaging in transfers to a pediatric emergency department

Objectives: Children are often transferred to a Pediatric Emergency Department (PED) for definitive care after completion of diagnostic imaging. There is a paucity of data on the concordance rates of interpretation of imaging studies between referral and PED. Our objective is to describe the rates and clinical impact of discordant interpretation of X-rays and CT in children transferred to a PED. Methods: This was a retrospective cohort study of patients over a 12-month period from 12/1/2017–11/30/2018 with X-ray (XR) and CT performed prior to transfer to our PED. We compared referral radiology interpretations to those of pediatric radiologists to determine concordance. Encounters with discordant imaging interpretations were further evaluated for clinical impact (none, minor or major) based on need for additional laboratory workup, consultation, and changes in management and disposition. Results: We analyzed 899 patient encounters. There were high rates of concordance in both XR and CT interpretation (668/743; 89.9%, 95% CI 0.87–0.91 and 205/235; 87.2%, 95% CI 0.82–0.91, respectively). XR discordance resulted in minor clinical impact in 34 patients (45%, 95% CI 0.35–0.57) and a major clinical impact in 28 patients (37%, 95% CI 0.27–0.49). CT discordance resulted in minor clinical impact in 10 patients (33%, 95% CI 0.19–0.51) of patients and major clinical impact in 15 patients (50%, 95% CI 0.33–0.67). The most common discordances with major clinical impact were related to pneumonia on XR chest and appendicitis or inflammatory bowel disease on CT abdomen. Conclusions: In patients transferred to the PED, concordance of XR and CT interpretations was high. A majority of discordant interpretations led to clinical impact meaningful to the patient and emergency medicine (EM) physician. Referring EM physicians might consider the benefit of pediatric radiology consultation upon transfer, especially for imaging diagnoses related to pneumonia, appendicitis, or inflammatory bowel disease.