Lung T1‐MRI and Multi‐Breath Washout Detect Longitudinal Changes in Children 6–11 Years Old After Beginning Elexacaftor/Tezacaftor/Ivacaftor (ETI) Therapy

MBW, spirometry, and lung T1-MRI are all capable of detecting lung airway and perfusion changes in cwCF 6-11 years of age following the start of ETI therapy. MBW and spirometry assessments were able to detect a sustained improvement in pulmonary function testing regardless of baseline lung status, while lung T1-MRI was able to detect significant improvements in lung perfusion in patients with more advanced lung disease. These findings, in combination with our prior cross-sectional findings, suggest that MBW and lung T1-MRI may provide complementary alternatives to chest CT and can be used to assess disease progression and/or response to therapy.