1. Neuroradiology Section; The University of Texas Health Science Center at San Antonio; Texas USA
2. Bayer Healthcare Pharmaceuticals; Montville New Jersey USA
3. St Joseph's Wayne Hospital; Paterson New Jersey USA
4. Radsource; Nashville Tennessee USA
5. Bayer Schering Pharma AG; Berlin Germany
6. Zwanger-Pesiri Radiology; Lindhurst New York USA