CT-guided radiolabelled aerosol studies for assessing pulmonary impairmentin children with bronchiectasis

Objective. To determine whether CT-guided mucociliary clearance studies all ow differentiation between bronchiectasis associated with primary ciliary d yskinesia (PCD) and those unrelated to congenital or genetically transmitte d defects. Materials and methods. Fifteen children aged 4-18 years with a CT diagnosis of bronchiectasis were included in the study. Six had PCD, while in nine c ases no congenital disorder was demonstrated. Results. CT showed bronchiectasis in 26 (29 %) of 90 lung regions. Radiolab elled aerosol studies were conducted globally for each lung and on the regi ons affected by bronchiectasis. Global half-time of activity (t(1/2)) value s of patients with PCD were significantly higher (P < 0.001) than those wit h bronchiectasis unrelated to congenital disorders. Among the 26 lung regions in which CT demonstrated bronchiectasis, regional clearance was abnormal in 24 cases. Patients with PCD showed no statistica lly significant difference between regional and global t(1/2) values. Patie nts with bronchiectasis unrelated to congenital disorders showed significan tly higher regional t(1/2) values in the affected regions with respect to t he corresponding global pulmonary t(1/2) (P < 0.06). Conclusions. The combination of morphological CT information with functiona l data concerning the clearance of radiolabelled aerosol adds to our unders tanding of pulmonary impairment in children with bronchiectasis. In particu lar, regional studies allow the recognition of different mucociliary cleara nce patterns in bronchiectasis associated with PCD and those unrelated to c ongenital or genetically transmitted defects.