Wisconsin cystic fibrosis chest radiograph scoring system: validation and standardization for application to longitudinal studies.
Koscik RE, Kosorok MR, Farrell PM, Collins J, Peters ME, Laxova A, Green CG, Zeng L, Rusakow LS, Hardie RC, et al. Pediatr Pulmonol. 2000 Jun; 29(6):457-67.