1. Neurosurgery Research Group, Biomedicum, Helsinki, Finland
2. Wihuri Research Institute, Biomedicum, Helsinki, Finland
3. Department of Vascular Surgery, Helsinki University Hospital, and University of Helsinki, Helsinki, Finland
4. Hemorrhagic Brain Pathology Research Group
5. Clinical Imaging Center, Kuopio University Hospital, Kuopio, Finland
6. Department of Neurosurgery, Helsinki University Hospital, and University of Helsinki, Helsinki, Finland
7. Department of Neurosurgery, Henan Province People's Hospital, Zhengzhou, China
8. Department of Neurosurgery