Methods
This study involved a retrospective analysis of the clinical data, PFT results and radiographic features of patients diagnosed with PIBO between 2011 and 2019 at the First Hospital of Jilin University. The study was approved by the research ethics committees of our institutions. All tests were ordered as part of clinical care of patients with PIBO. All participating patients and the parents or legal guardians verbally consented to be included in the study.