1. CREATIS, INSA 502, 69621 Villeurbanne Cedex, France
2. European Synchrotron Radiation Facility, BP 220, 38043 Grenoble Cedex, France
3. Mayo Clinic, Alfred 2-409, Rochester, MN 55905, USA
4. IBT, ETH, Moussonstrasse 18, CH-8044, Zürich, Switzerland