[1] Univ Aquila, Dept Phys & Chem Sci, Via Vetoio, I-67100 Laquila, Italy
[2] Washington Univ, Sch Med, Dept Radiol, 4525 Scott Ave,Campus Box 8225, St Louis, MO 63110 USA
[3] Hamamatsu Univ Sch Med, Inst Med Photon Res, Dept Biomed Opt, Higashi Ku, 1-20-1 Handayama, Hamamatsu, Shizuoka 4313192, Japan
[4] PTB, Dept Biomed Opt, Abbestr 2-12, D-10587 Berlin, Germany