Obstructive lung disease in children after allogeneic bone marrow transplantation: evaluation with high-resolution CT.

OBJECTIVE Obstructive lung disease is a major complication of bone marrow transplantation related to graft-versus-host disease. The purpose of this study was to determine the usefulness of high-resolution CT to evaluate obstructive lung disease occurring in children after bone marrow transplantation. MATERIALS AND METHODS Ten high-resolution CT scans of the lungs were obtained in seven children who developed chronic obstructive lung disease after bone marrow transplantation. All seven patients had chronic graft-versus-host disease. Spirometry, the gold standard test, confirmed airflow obstruction in each case, five prior to high-resolution CT. Two patients were too young to have spirometry until 10 and 15 months respectively after successful high-resolution CT. Selected images from these studies were randomized with similar images from five control subjects and reviewed blindly. All images from scans in patients with obstructive lung disease were analyzed retrospectively for parenchymal hypoattenuation, bronchial dilatation, bronchial wall thickening, and abnormal parenchymal opacity. Expiratory air-trapping was assessed on cine high-resolution CT done in four cases. RESULTS Three blinded observers each correctly identified all five controls among 15 high-resolution CT examinations. No scan from a patient with obstructive lung disease was considered normal. Areas of parenchymal hypoattenuation affected 35 of 35 lobes of the lung. Expiratory air-trapping was shown by cine high-resolution CT. Subsegmental or segmental bronchial dilatation was seen in 23 of 25 lobes in five patients. Bronchial wall thickening was not a prominent feature. Increasing abnormality was demonstrated in three patients on follow-up high-resolution CT. The high-resolution CT abnormalities were similar to those reported in patients with bronchiolitis obliterans. CONCLUSION High-resolution CT of the lungs can show extensive abnormality in children who develop chronic obstructive lung disease after bone marrow transplantation. High-resolution CT is a useful noninvasive technique in the evaluation of this disease.