Certainty Language Use in Pediatric Radiology: A Single-Institution Analysis.

BACKGROUND: Radiologists often employ diagnostic certainty phrases (DCPs) to convey levels of confidence in imaging interpretations. Prior research in adult radiology demonstrated wide variability in DCP usage, potentially complicating communication with clinicians and patients. Little is known about these practices in pediatric radiology. We aimed to characterize DCP use among pediatric radiologists in a large academic institution. MATERIALS AND METHODS: We retrospectively analyzed radiology reports from a freestanding pediatric hospital system between October 2023 and September 2024. From 309,751 pediatric imaging reports meeting inclusion criteria, 10,000 were randomly sampled to identify DCPs using a natural language processing pipeline (GPT-4o, OpenAI, San Francisco, California). After exclusions and manual review, 122 unique DCPs were identified. We then counted the occurrence of these 122 DCPs across the remaining 309,751 radiology report first impressions. Usage rates were evaluated across patient demographics, imaging modalities, clinical settings, and radiologist seniority. Statistical significance was assessed using two-sided one-sample t tests with significance assigned to values P ≤ .001. RESULTS: Of the 309,751 analyzable reports, 20.9% contained at least one DCP in the first impression. The mean DCP frequency was 0.27 per report. MRI (0.54, P < .001), patients aged 1 to 5 years (0.34, P < .001), and emergency cases (0.31, P < .001) showed significantly higher usage. Midcareer and early-career radiologists employed more DCPs (0.30, P < .001) than senior radiologists (0.22, P < .001). The most common phrases included "likely," "could represent," and "cannot rule out." CONCLUSIONS: DCPs are frequently used in pediatric radiology, with variability influenced by modality, patient age, clinical context, and radiologist seniority. Such variability may compound existing uncertainty of the clinical diagnostic process and possibly indicate an opportunity for standardized uncertainty reporting approaches.