[1] Department of Neuroradiology,
[2] San Raffaele Hospital,undefined
[3] Via Olgettina 60,undefined
[4] I-20132 Milan,undefined
[5] Italy,undefined
[6] e-mail: simionato.franco@hsr.it,undefined
[7] Tel.: + 39-02-26 43 27 26,undefined
[8] Fax: + 39-02-26 43 30 11,undefined