1. Mallinckrodt Institute of Radiology; St. Louis Missouri USA
2. Brigham and Women's Hospital; Harvard Medical School; Boston Massachusetts USA
3. Health Time; Clinica Las Nieves; Jaen Spain
4. University Hospitals; Case Western Reserve University; Cleveland Ohio USA
5. Health Time; Hospital de la Cruz Roja and San Juan de Dios; Cordoba Spain
6. University of California-San Francisco; San Francisco California USA
7. Massachusetts General Hospital; Harvard Medical School; Boston Massachusetts USA