Comparison of ultrasound with plain radiography and CT for the detection of mediastinal lymphadenopathy in children with tuberculosis

Background: Lymphadenopathy, with or without parenchymal abnormality, is the radiological hallmark of primary tuberculosis (TB) in children. However, lymph node enlargement may pass undetected on plain chest radiographs. Ultrasonography provides complementary information to that obtained by radiographs. Objective: To assess the clinical value of US for the detection of mediastinal lymphadenopathy in children with a positive intradermal tuberculin test. Materials and methods: Thirty-two children with a mean age of 6 years and a positive Mantoux test underwent chest radiography (frontal and lateral) and US (suprasternal and left parasternal access routes). Chest CT was performed at the discretion of the attending physician in six cases. Results: Eleven children had clinical symptoms and 90% a recent contact with a person with active TB. In 90.5% of children with chest radiographic images compatible with TB, coincident findings in the mediastinal US study were found. By comparison, 66.7% of those with normal chest radiography had evidence of mediastinal lymphadenopathy on the US scan. In all cases but one, US and CT findings agreed. Conclusions: Mediastinal US is useful for the detection of enlarged lymph nodes in children with a positive tuberculin reaction and normal chest radiography.