A New Simple to Use Chest CT Scoring System: Validation Study

Current chest computed tomography (CT) based scoring systems are complex.

Validity of new simple and easy to use chest CT scoring system was determined in pwCF with varying severity of lung disease.

Three pulmonary physicians scored 60 chest CT scans in 30 pwCF, ages 12-60 years, done at initiation and at 1-year on ETI therapy and scores were correlated with ppFEV₁.

Interrater agreement among three raters, determined by intraclass correlation coefficient (ICC) (95% confidence interval [CI]) scores in total cohort, was 0.83 (0.72, 0.91), for bronchiectasis (BEC), 0.83 (0.72, 0.91) for mucus plugging (MP), and for bronchial wall thickness (BWT) and parenchymal lung disease (PLD) was 0.56 (0.35, 0.74) and 0.7 (0.54, 0.83) respectively (all in the moderate to good range). Intrarater reliability (4-6 weeks apart) on 10 pwCF (20 CT scans) in total cohort was excellent, ranging from 0.92 to 0.98. For individual components it was excellent for BEC, good to excellent for PLD and MP, and moderate for BWT. ppFEV₁ correlated well with total chest CT scores, r = -0.75 (p < 0.001). For individual components, the strongest correlations were noted with BEC (-0.71), PLD (-0.73) and MP (-0.68). With ETI therapy, median (interquartile range [IQR]) total scores improved from 49 (42, 54) to 23.5 (18, 31.7) (p < 0.001) in total cohort and similar patterns were also seen in individual components (BEC, BWT, MP, AT, and PLD).

Our scoring system was validated with acceptable interrater and intrarater agreement and was able to quantify expected changes with therapy.