Cystic Fibrosis Specific Computed Tomography Scoring

Abstract

This article presents a review and discussion of the current knowledge regarding cystic fibrosis (CF)-specific scoring of chest computed tomography (CT) scans. First, the basic principles of CT scoring systems in CF are described. Second, between- and within-observer variability of a composite CT score and of component CT scores are reviewed, and issues regarding training of CT scan readers discussed. Third, arguments regarding whether CT scoring systems are ready to be used in clinical studies as a surrogate endpoint are summarized. The between- and within-observer variability of the present CT composite scoring systems is low enough to be useful for clinical studies, although the variability for some of the component scores is larger than for others. Scoring systems fulfill the requirements for surrogate endpoints for CF lung disease, but this role could be further strengthened by including CT scans in large trials and demonstrating the correlation with true endpoints. The conclusion presented is that, given the experience of the variety of published scoring systems, it is important to develop a consensus CT scoring system for future studies in CF. Such a scoring system should evaluate all lung lobes individually and include all relevant CT findings in CF. Development of reference images for the components of this system will be important in reducing the variability between observers and to train new readers.