1. Department of Medicine, Rheumatology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
2. Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
3. Department of Radiology, National Jewish Health, Denver, CO, USA
4. University of Washington, Seattle, WA, USA
5. University of Florence, Florence, Italy
6. Department of Medicine, Pulmonary & Critical Care, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA