1. Department of Pediatric Oncology, Hematology and Transplantology, Poznan University of Medical Sciences, Poznan, Poland;
2. Department of Neurology and Cerebrovascular Disorders, Poznan University of Medical Sciences, Poznan, Poland;
3. Department of Neuroradiology, Poznan University of Medical Sciences, Poznan, Poland;
4. Department of Pediatric Radiology, Poznan University of Medical Sciences, Poznan, Poland