1 Department of Cardiothoracic, Transplant and Vascular Surgery, Hannover Medical School, Hannover, Germany.
2 Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany.
3 Department of Respiratory Medicine and Infectious Diseases, Hannover Medical School, Hannover, Germany.
4 German Center for Lung Research (Deutsches Zentrum für Lungenforschung/biomedical research in end-stage and obstructive lung disease hannover), Hannover, Germany.