Thoracic findings of systemic diseases at high-resolution CT in children.

Pulmonary involvement in systemic diseases is common, but the radiographic appearance of early-stage pulmonary changes is often subtle. Computed tomography (CT) has higher sensitivity and specificity than radiography, and high-resolution CT is the method of choice for accurate assessment of diffuse parenchymal lung disease. Even with reductions in the peak voltage and tube charge to minimize the exposure of pediatric patients to radiation, CT performed with a meticulous acquisition technique can provide detailed information. In some cases, high-resolution CT may depict clinically silent lung lesions. The information provided by CT is invaluable for planning therapy in pediatric patients with pulmonary involvement in connective tissue disease (eg, juvenile rheumatoid arthritis, dermatomyositis, systemic sclerosis, systemic lupus erythematosus, or mixed connective tissue disease), vasculitis, a primary or acquired immune deficiency disorder, immotile cilia syndrome, cystic fibrosis, or Langerhans cell histiocytosis.