1. Department of Electroradiology, Poznan University of Medical Sciences, 61-866 Poznan, Poland
2. Department of Adult Neurology, Medical University of Gdansk, 80-210 Gdansk, Poland
3. Department of Medical Physics, Greater Poland Cancer Centre, 61-866 Poznan, Poland
4. Department of Radiotherapy II, Greater Poland Cancer Centre, 61-866 Poznan, Poland