1. Division of Epidemiology and Community Health University of Minnesota School of Public Health Minneapolis Minnesota USA
2. Department of Preventive Medicine Northwestern University Feinberg School of Medicine Chicago Illinois USA
3. Division of Pulmonary and Critical Care Medicine Northwestern University Feinberg School of Medicine Chicago Illinois USA
4. Division of Pulmonary and Critical Care Medicine Brigham and Women’s Hospital Boston Massachusetts USA
5. Applied Chest Imaging LaboratoryBrigham and Women’s Hospital Boston Massachusetts USA
6. Department of Pathology and Laboratory Medicine University of Minnesota School of Medicine Minneapolis Minnesota USA
7. Department of Biostatistics University of Minnesota School of Public Health Minneapolis Minnesota USA