Radiographic imaging in pediatric suspected foreign body ingestion: potential for dose reduction through collimation and exposure strategies

BACKGROUND: Foreign body ingestion constitutes a common emergency in children. Radiography is essential for confirming presence, type, and location of ingested objects. International guidelines recommend broad anatomical coverage from the neck to the pelvis; however, the impact of radiographic exposure parameters and collimation on radiation dose remains underexplored. OBJECTIVE: To evaluate the effects of different scan protocols on radiation dose in pediatric foreign body ingestion. MATERIALS AND METHODS: Two-hundred-twenty-one radiographs from 183 pediatric patients (median age 2.8 years [interquartile range 1.5-5.5 years]; 112 males, 71 females) performed between September 2019 and April 2025 were retrospectively analyzed. Radiographs were categorized as neck-upper abdomen, extended collimation including pelvis, or abdomen only. Notably, the first two protocols used chest radiograph exposure parameters. Data included patient demographics, foreign body type and location, radiographic protocol, dose-area product, and estimated effective dose. RESULTS: A foreign body was detected in 55.7% of radiographs, most of them in the stomach (59.4%). Coins were most common (31.7%), followed by button batteries (13.8%) and magnets (12.2%). Dose-area products were comparable between standard neck-to-upper-abdomen and extended neck-to-pelvis collimation but were markedly higher for abdomen-only imaging (P<0.001). Effective dose increased with extended collimation (P<0.05) and was highest for abdomen-only radiographs (0.053 mSv [0.034-0.086 mSv], P<0.001). No differences were observed in patient age or repeat imaging rates. CONCLUSION: In suspected pediatric foreign body ingestion, collimation and exposure parameters substantially influence radiation dose. Low-dose chest parameters combined with restrictive collimation minimize radiation exposure, whereas abdominal radiographs carry higher dose, attributable predominantly to the abdominal exposure parameters employed.