Gut Imaging for Function and Transit in Cystic Fibrosis 3 Junior

Recently trial data has shown that the medicine KaftrioTM (Elexacaftor/ Tezacaftor/ Ivacaftor) improves lung function in children aged 6 to 11 years who have cystic fibrosis (CF). This has led to it being licensed for use in the UK in 2022 and is now being prescribed in this age group. There is little information in trials however that shows the effect KaftrioTM (ETI) has on the gut or liver in this age group. Previous studies in the GIFT-CF series (NCT 03566550, NCT04006873 and NCT04618185) has found differences in the functioning of the gut between adults with CF and healthy controls but it is not known whether these differences are present in those aged 6 to 11 years. This study is a significant amendment of the GIFT-CF3 protocol (NCT04618185) that aims to measure gut function using magnetic resonance imaging (MRI) in children with CF before and after starting ETI. This study also aims to opportunistically measure lung function and structure using MRI and explore how the liver can be measured using MRI in this age group. The study is split into 2 stages. The first is a pilot stage using the modified GIFT-CF protocol recruiting 3 children with CF before starting ETI and 3 healthy volunteers. This is to determine we are able to successfully perform these scans in these age groups. If successful, the second stage will recruit a further 12 children with CF before they start ETI. This will take our cohort up to 15 children with CF. This cohort will then be rescanned 6 months after starting ETI using the same scan protocol.