1 Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Aapistie 7A, POB 5000, 90014 Oulu, Finland.
2 Department of Internal Medicine, Mikkeli Central Hospital, 50100 Mikkeli, Finland.
3 Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Aapistie 7A, POB 5000, 90014 Oulu, Finland; Department of Diagnostic Radiology, Oulu University Hospital, 90029 Oulu, Finland; Medical Research Center, University of Oulu and Oulu University Hospital, 90014 Oulu, Finland.