1 Department of Pediatrics/Pediatric Nephrology, University Hospital of Ioannina, Stavros Niarchos Avenue, 45 500, Ioannina, Greece.
2 Department of Radiology, University Hospital of Ioannina, Ioannina, Greece.
3 Department of Pediatrics/Pediatric Nephrology, University Hospital of Ioannina, Stavros Niarchos Avenue, 45 500, Ioannina, Greece. eksiomou@yahoo.gr.