1. Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts
2. Department of Interventional Radiology, Massachusetts General Hospital, Boston, Massachusetts
3. Department of Interventional Radiology, Kaiser Permanente, Denver, Colorado
4. Division of Vascular and Interventional Radiology, Department of Radiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado
5. Diagnostic and Interventional Radiology, Advanced Radiology Services, Grand Rapids, Michigan