[1] Univ Trieste, Cattinara Hosp, Dept Radiol, Azienda Osped Univ,Osped Riuniti Trieste, I-34149 Trieste, Italy
[2] Osped Riuniti, Azienda Osped Univ, Osped Maggiore, Dept Radiol, Trieste, Italy
[3] Inst Maternal & Child Hlth IRCCS Burlo Garofolo, Dept Paediat Radiol, Trieste, Italy
[4] Bambino Gesu Pediat Hosp, Neonatal Intens & Subintens Care Unit, Rome, Italy
[5] Univ Milan, Dept Paediat, San Paolo Hosp, Milan, Italy
[6] Univ Florence, Meyer Childrens Hosp, Florence, Italy
[7] Univ Roma La Sapienza, Dept Radiol, Azienda Osped St Andrea, I-00185 Rome, Italy
[8] Univ Cattolica Sacro Cuore, Dept Paediat, Div Neonatol, Univ Hosp A Gemelli, I-00168 Rome, Italy
[9] Inst Maternal & Child Hlth IRCCS Burlo Garofolo, Div Neonatol, Trieste, Italy