Pediatric diffuse lung disease: diagnosis and classification using high-resolution CT.

OBJECTIVE: Our purpose was to categorize high-resolution CT findings in children with diffuse lung disease and to evaluate the accuracy of diagnoses made using CT.
MATERIALS AND METHODS: The chest radiographs and high-resolution CT scans of 20 children (1-16 years old; median, 9 years old) with biopsy-proven chronic diffuse lung diseases were reviewed separately by two independent chest radiologists. Thirteen types of diffuse lung disease were included in the study. Radiographic and CT features were noted, and three choices of diagnosis were recorded, with the confidence level.
RESULTS: Diagnoses were made with a high degree of confidence (definite or probable) in 25 of 40 interpretations of CT scans, compared with only five of 40 interpretations of chest radiographs (p < .001). Fourteen (56%) of the 25 confident first-choice diagnoses on CT scans were correct, compared with two (40%) of the five interpretations on chest radiographs. Diseases were classified as belonging to one of five distinct groups on the basis of dominant CT features. Airway disease (n = 5) (bronchiolitis obliterans or bronchocentric granulomatosis) showed geographic hyperlucency on CT. Septal disease (n = 4) (lymphangiomatosis, hemangiomatosis, or microlithiasis) showed septal thickening. Infiltrative lung disease (n = 7) (desquamative interstitial pneumonitis, hypersensitivity pneumonitis, or lymphoid interstitial pneumonitis) showed ground-glass opacity. Air-space disease (n = 3) (aspiration, vasculitis, or bronchiolitis obliterans organizing pneumonia) showed lung consolidation. Langerhans' histiocytosis (n = 1) showed cysts and nodules. Surprisingly little overlap was seen among these groups.
CONCLUSION: CT increases the level of diagnostic confidence for pediatric infiltrative lung disease, improves diagnostic accuracy, and provides a useful classification system.