RADIOAEROSOL ASSESSMENT OF LUNG IMPROVEMENT IN CYSTIC-FIBROSIS PATIENTS TREATED FOR ACUTE PULMONARY EXACERBATIONS

We compared bronchopulmonary distribution homogeneity of a radioaerosol before and after hospitalization in 20 patients with cystic fibrosis (CF) with pulmonary exacerbations in order to assess lung improvement. Deposition homogeneity was quantified in terms of skew (an index of distribution symmetry), derived from frequency distribution histograms generated from gamma camera images of the lungs following radioaerosol inhalation. Lower skew values indicate enhanced distribution homogeneity. Right lung skew (RLS) was significantly reduced following therapy (1.00 +/- 0.49 to 0.84 +/- 0.47), whereas skew in the left lung was unchanged (0.95 +/- 0.38 to 0.87 +/- 0.40). The reduction in RLS was significant in patients with Shwachman-Kulczycki (SK) clinical scores < 50 (1.27 +/- 0.53 to 0.90 +/- 0.42), but not in patients with scores > 50 (0.81 +/- 0.38 to 0.80 +/- 0. 52). These results indicate that treatment affected the right lung more than the left lung, particularly in patients with SK scores < 50, and suggests that radioaerosol lung imaging may be valuable in identifying sites of impairment to be targeted during treatment. Statistically, skew was less sensitive an indicator of acute change than several other clinical indices that improved following hospital treatment.