1 Department of Clinical Physiology and Nuclear Medicine, University Hospital of Copenhagen, Rigshospitalet, Copenhagen, Denmark. lise.borgwardt@regionh.dk.
2 Department of Paediatrics, University Hospital of Copenhagen, Rigshospitalet, Copenhagen, Denmark.
3 Department of Clinical Physiology and Nuclear Medicine, University Hospital of Copenhagen, Rigshospitalet, Copenhagen, Denmark.
4 Department of Paediatrics, Odense University Hospital, Odense, Denmark.