1. Division of Paediatric Respiratory Medicine and Allergology, Department of Paediatrics, Inselspital Bern University Hospital, University of Bern Bern Switzerland
2. Division of Paediatric Pulmonology and Allergology, Department of Pediatrics Amalia Children's Hospital, Radboud University Medical Centre Nijmegen The Netherlands
3. Division of Radiological Physics Department of Radiology University of Basel Hospital Basel Switzerland
4. Department of Biomedical Engineering University of Basel Allschwil Switzerland
5. Institute for Biomedical Engineering University and ETH Zurich Zurich Switzerland