1. Dipartimento di Fisica “Ettore Pancini”; Università di Napoli Federico II; Via Cintia I-80126 Napoli Italy
2. INFN Sezione di Napoli; I-80126 Napoli Italy
3. National Co-ordinating Centre for the Physics of Mammography (NCCPM); Royal Surrey County Hospital; Guildford GU2 7XX UK
4. Department of Physics; University of Surrey; Guildford GU2 7XH UK
5. Dutch Reference Centre for Screening (LRCB); P.O. Box 6873 6503 GJ Nijmegen The Netherlands
6. Department of Electronics; Technical University of Varna; 1 Studentska Str Varna 9010 Bulgaria
7. Department of Radiology and Imaging Sciences; Emory University School of Medicine; 1701 Upper Gate Drive Northeast, Suite 5018 Atlanta GA 30322 USA
8. Department of Biomedical Engineering; Emory University and Georgia Institute of Technology; Atlanta GA 30322 USA
9. Department of Radiology and Nuclear Medicine; Radboud University Medical Centre; P.O. Box 9101 6500 HB Nijmegen The Netherlands