1. Department of Radiology and Imaging Sciences, Division of Emergency Radiology, Emory University Hospital Midtown, 550 Peachtree Rd, Atlanta, GA 30308.
2. Baqai School of Medicine, Baqai Medical University, Karachi, Pakistan.
3. Department of Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX.
4. Department of Radiology, Vancouver General Hospital, Vancouver, BC, Canada.