RT Journal Article SR Electronic T1 The quantitative link of lung clearance index to bronchial segments affected by bronchiectasis JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 82 OP 84 DO 10.1136/thoraxjnl-2017-210496 VO 73 IS 1 A1 Verbanck, Sylvia A1 King, Gregory G A1 Zhou, Wenxiao A1 Miller, Anne A1 Thamrin, Cindy A1 Schuermans, Daniel A1 Ilsen, Bart A1 Ernst, Caroline W A1 de Mey, Johan A1 Vincken, Walter A1 Vanderhelst, Eef YR 2018 UL http://thorax.bmj.com/content/73/1/82.abstract AB In adult patients with cystic fibrosis (CF), the lung clearance index (LCI) derived from the multiple breath washout relates to both acinar and conductive ventilation heterogeneity. The latter component predicts an association between LCI and the number of bronchial segments affected by bronchiectasis. Here, we experimentally demonstrated this association in patients with CF, and also examined an ancillary group of patients with non-CF bronchiectasis. We conclude that lung disease severity in terms of number of bronchial segments results in an associated LCI increase, likely constituting a portion of LCI that cannot be reversed by treatment in patients with CF lung disease.