Radiographic Outcomes in Paediatric Bronchiectasis and Factors Associated with Reversibility.

Conventionally considered irreversible, bronchiectasis reversibility in children has been demonstrated in small studies. However, the factors associated with radiographic reversibility in bronchiectasis have yet to be defined. In a large cohort of children with bronchiectasis, we aimed to determine (a) if and to what extent bronchiectasis is reversible and (b) factors associated with radiographic chest high resolution computed tomography (cHRCT) resolution. We identified children with bronchiectasis who had a repeat multidetector HRCT between 2010-2021. We excluded those with cystic fibrosis, surgical pulmonary resection, traction bronchiectasis only, or lobar opacification. cHRCT scans were scored using the modified Reiff-score (MRS) with a paediatric correction. Resolution was defined as absence of abnormal broncho-arterial ratio (>0.8) on the second cHRCT. We included 142 children (median age=5years: IQR 2.6-7.4), Inter- and intra-rater agreement in MRSs was excellent (weighted kappa=0.83-0.86 and 0.95 respectively). Radiographically resolution was documented in 57/142 (40.1%), improved in 56/142 (39.4%), unchanged/worse in 29/142 (20.4%). This first large cohort confirms bronchiectasis in children is often reversible with appropriate management. Younger aged children and those with lesser radiographic severity at diagnosis were most likely to achieve radiographic reversibility whilst those with