1. Denver Health , Denver, CO , USA
2. Massachusetts General Hospital, Department of Radiology , Boston, MA , USA
3. University of Cincinnati Medical Center, Department of Radiology , Cincinnati, OH , USA
4. Liberty Hospital, Department of Radiology , Kansas City, MO , USA
5. Alliance Radiology , Kansas City, MO , USA
6. University of Missouri–Kansas City School of Medicine, Department of Radiology , Kansas City, MO , USA