1. Biomedical Photonic Imaging Group, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, P.O. Box 217, 7500 AE Enschede, the Netherlands
2. Center for Breast Care, Medisch Spectrum Twente Hospital, P.O. Box 50000, 7500 KA Enschede, the Netherlands
3. Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, P.O. Box 2270, 1100 DE Amsterdam, the Netherlands