Clinical significance of lung perfusion defects in children with post-infectious bronchiolitis obliterans.

Clinical significance of segmental lung perfusion defects in children with bronchiolitis obliterans (BO), have not been reported before. The aim of this study was to evaluate clinical significance of lung perfusion defects in children with BO and to reveal its impact on follow up. The study included 38 children aged 9 to 60 months (17.8 + or - 13.4 months) with BO. Diagnosis was based on persistent respiratory findings beyond six weeks and oligemic-mosaic pattern in lung high resolution computerized tomography. Chest X-ray, 24 hour esophageal pH monitoring, sweat chloride test, immunoglobulin levels and respiratory viral screening were carried out in all. Lung perfusion scintigraphy was carried out at least three months after the first clinical sign of BO. Perfusion defects were scored. Scintigraphy demonstrated perfusion defects in 24 (63.2%) patients but was normal in 14 (36.8%). Number of segments having perfusion defects was 2.9 + or - 2.6. Mean number of exacerbations and days of hospitalization during the first year of follow up were 4.7 + or - 4.4 and 26.9 + or - 29.8 respectively. It was detected that number of perfusion defects correlated significantly with the number of exacerbations and duration of hospitalization (r= 0.66 and p= 0.00). In conclusion, number and extent of segments with perfusion defects in lungs of children with BO are correlated with clinical severity. Therefore, evaluation of lung perfusion status may aid in clinical determination of disease severity and its follow-up.