Authors:
Ramsey KA, Rosenow T, Turkovic L, Skoric B, Banton G, Adams AM, et al.
Authors notes:
American Journal of Respiratory and Critical Care Medicine. 2016;193(1):60-7.
Keywords:
cystic fibrosis, imaging, infant, multiple-breath washout, adolescent, age, bronchiectasis, case control study, computer assisted tomography, Tomography, X-Ray Computed
Abstract:
RATIONALE: The lung clearance index is a measure of ventilation distribution derived from the multiple-breath washout technique.
It has been suggested as a surrogate for chest computed tomography to detect structural lung abnormalities in individuals with cystic fibrosis (CF); however, the associations between lung clearance index and early structural lung disease are unclear.
OBJECTIVES: We assessed the ability of the lung clearance index to reflect structural lung disease on the basis of chest computed tomography across the entire pediatric age range.
METHODS: Lung clearance index was assessed in 42 infants (ages 0-2 yr), 39 preschool children (ages 3-6 yr), and 38 school-age children (7-16 yr) with CF before chest computed tomography and in 72 healthy control subjects.
Scans were evaluated for CF-related structural lung disease using the Perth-Rotterdam Annotated Grid Morphometric Analysis for Cystic Fibrosis quantitative outcome measure.
MEASUREMENTS AND MAIN RESULTS: In infants with CF, lung clearance index is insensitive to structural disease.
In preschool children with CF, lung clearance index correlates with total disease extent.
In school-age children, lung clearance index correlates with extent of total disease, bronchiectasis, and air trapping.
In preschool and school-age children, lung clearance index has a good positive predictive value (83-86%) but a poor negative predictive value (50-55%) to detect the presence of bronchiectasis.
CONCLUSIONS: These data suggest that lung clearance index may be a useful surveillance tool to monitor structural lung disease in preschool and school-age children with CF.
However, lung clearance index cannot replace chest computed tomography to screen for bronchiectasis in this population.