Predictive value of chest CT in patients with cystic fibrosis: A single-center 10-year experience

OBJECTIVE. The objective of our study was to assess the accuracy of one of the most used scoring systems, the Bhalla scoring system, in the detection of lung impairment in patients with cystic fibrosis and in the prediction of cystic fibrosis progression. MATERIALS AND METHODS. From the database of our center, 300 CT examinations performed between 1991 and 2001 were reviewed. Pulmonary function tests performed the same day as radiologic assessment were available. Of this group, 145 examinations were retrospectively included, referring to 87 patients with confirmed cystic fibrosis and a mean age (+/- SD) of 15.6 +/- 8.4 years ( range, 9 months-38 years). Thirty patients underwent one CT examination, 56 underwent two examinations, and one patient underwent three examinations. The mean interval between two examinations was 36.5 months. The 145 examinations were independently reviewed by three radiologists who were blinded to the clinical and pulmonary function test results. The CT examinations were assessed using the scoring system proposed by Bhalla and colleagues. RESULTS. CT assessed using the Bhalla scoring system is mildly correlated with functional pulmonary test results and has high interobserver reproducibility. The CT score significantly changed between scans obtained in a mean interval of 36.5 months, whereas functional pulmonary test results did not, suggesting that CT is more sensitive than function tests for detecting small changes. However, the variation in CT scores did not predict progression of functional pulmonary test results or progression of CT findings between scans. CONCLUSION. CT assessment based on the Bhalla scoring system is more sensitive than pulmonary function tests in detecting initial morphologic changes. However, we found no evidence of the predictive value of CT.