1. University of Minnesota Medical School, Minneapolis, MN, USA
2. Department of Medicine, Division of Rheumatic and Autoimmune Diseases, University of Minnesota Medical School, Minneapolis, MN, USA
3. Department of Radiology, University of Minnesota Medical School, Minneapolis, MN, USA
4. Department of Laboratory Medicine & Pathology, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, MN 55455, USA