Study design and setting
This study was performed in conjunction with the PICTURE study (Pulmonary Magnetic Resonance Imaging of Ex-preterm Children with and without Bronchopulmonary Dysplasia to Understand Risk of Emphysematous Changes; clinicaltrials.gov: NCT02921308)13. The PICTURE study is a multicentre, cross-sectional study which aimed to evaluate the use of ultra-short echo time MRI to assess lung structure in children born extremely preterm with and without BPD. This study was performed at three tertiary pediatric hospitals: the Children’s Hospital of Eastern Ontario (Ottawa, Ontario), The Hospital for Sick Children (Toronto, Ontario), and the Centre Hospitalier Universitaire Sainte-Justine (Montreal, Quebec). Local research ethics board approval was obtained at each of the participating sites.