1. Paediatrics and Neonatology Unit, University of Parma, Guglielmo da Saliceto Hospital, 43121 Piacenza, Italy
2. Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy
3. Unit of Paediatric Radiology, University Hospital of Parma, 43126 Parma, Italy
4. Unit of Paediatrics, Department of Mother and Child, University Hospital of Parma, 43126 Parma, Italy