1 Medical Imaging Center, Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands. r.h.j.a.slart@umcg.nl.
2 Biomedical Photonic Imaging Group, University of Twente, Enschede, The Netherlands. r.h.j.a.slart@umcg.nl.
3 Multi-Modality Medical Imaging Group, Technical Medical Centre, University of Twente, Enschede, The Netherlands.
4 Department of Surgery, Rijnstate, Arnhem, The Netherlands.