[1] Univ Oulu, Res Grp Med Imaging Phys & Technol, Fac Med, Res Unit Nursing Sci & Hlth Management, POB 5000, FI-90014 Oulu, Finland
[2] Univ Oulu, Res Grp Med Imaging Phys & Technol, Oulu, Finland
[3] Oulu Univ, Oulu Business Sch, Martti Ahtisaari Inst, Oulu, Finland
[4] Tech Res Ctr Finland, VTT, Oulu, Finland
[5] Oulu Univ Hosp, Med Res Ctr Oulu, Dept Children & Women, Oulu, Finland