Pediatric Chest CT at Chest Radiograph Doses: When is the ultralow-dose chest CT clinically appropriate?

PurposeComputed tomography (CT) use in emergency departments represents a significant contribution to pediatric patients' exposure to ionizing radiation. Here, we evaluate whether ultralow-dose chest CT can be diagnostically adequate for other diagnoses and whether model-based iterative reconstruction (MBIR) can improve diagnostic adequacy compared to adaptive statistical iterative reconstruction (ASIR) at ultralow doses.MethodsTwenty children underwent chest CTs: 10 standard-dose reconstructed with ASIR and 10 ultralow-dose reconstructed with ASIR and MBIR. Four radiologists assessed images for their adequacy to exclude five hypothetical diagnoses: foreign body, fracture, lung metastasis, pulmonary infection, and interstitial lung disease. Additionally, pairwise comparison for subjective image quality was used to compare ultralow-dose chest CT with ASIR and MBIR. Radiation dose and objective image noise measures were obtained.ResultsFor exclusion of an airway foreign body, the adequacy of ultralow-dose CT was comparable to standard-dose (p=0.6). For the remaining diagnoses, ultralow-dose CT was inferior to standard-dose (p=0.03