title: Chest imaging in cystic fibrosis studies: What counts, and can be counted?
abstract: BACKGROUND
  The dawn of precision medicine and CFTR modulators require more detailed assessment of lung structure in cystic fibrosis (CF) clinical studies. Various imaging markers have emerged and are measurable, but clarity is needed to identify what markers should count for clinical studies. High-resolution chest computed tomography (CT) scoring has yielded sensitive markers for the study of CF disease progression. Once completed, CT scores from ongoing randomized controlled trials can be used to examine relationships between imaging endpoints and therapeutic effectiveness. Similarly, Magnetic Resonance Imaging (MRI) is in development to generate structural as well as functional markers.
  
  
  RESULTS
  The aim of this review is to characterize the role of currently available CT and MRI markers in clinical studies, and to discuss study design, data processing and statistical challenges unique to these endpoints in CF studies. Suggestions to overcome these challenges in CF studies are included.
  
  
  CONCLUSIONS
  To maximize the potential of CT and MRI markers in clinical studies and advance treatment of CF disease progression, efforts should be made to conduct longitudinal randomized controlled trials including these modalities, develop data repositories, promote standardization and conduct reproducible research.
authors.affiliation: Division of Biostatistics & Epidemiology and Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States.
authors.forename: Rhonda
authors.initials: R
authors.lastname: Szczesniak
authors.affiliation: Telethon Kids Institute, West Perth, Australia.
authors.forename: Lidija
authors.initials: L
authors.lastname: Turkovic
authors.affiliation: Department of Biostatistics, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Eleni-Rosalina
authors.initials: ER
authors.lastname: Andrinopoulou
authors.affiliation: Department of Pediatric Pulmonology and Allergology, The Netherlands; Department of Radiology, Erasmus MC-Sophia Children's Hospital, Rotterdam, The Netherlands. Electronic address: h.tiddens@erasmusmc.nl.
authors.forename: Harm A W M
authors.initials: HAWM
authors.lastname: Tiddens
mesh_terms: D003550:Cystic Fibrosis / Q000175:diagnosis / Q000503:physiopathology; D018450:Disease Progression; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Cystic fibrosis; Endpoints; Imaging analysis; Outcome measures; Reliability; Surrogate endpoints