1. Department of Clinical Science-Neurosciences, Radiation Physics, Biomedical Engineering, Umeå University, Umeå, Sweden.
2. Department of Surgery and Perioperative Sciences, Radiation Physics, Biomedical Engineering, Umeå University, Umeå, Sweden.
3. Department of Radiation Sciences, Radiation Physics, Biomedical Engineering, Umeå University, Umeå, Sweden.