1. a Department of BioMedical Engineering , University Medical Center Groningen and University of Groningen , PO Box 196, 9700 AD Groningen , The Netherlands
2. b Department of Surgery , University Medical Center Groningen and University of Groningen , P. Box 196, 9700 AD Groningen , The Netherlands
3. c BioOptical Imaging Center Groningen, University Medical Center Groningen and University of Groningen , PO Box 196, 9700 AD Groningen , The Netherlands