[1] Department of Radiology,
[2] DICMI,undefined
[3] University of Genoa,undefined
[4] Largo R. Benzi,undefined
[5] 8,undefined
[6] 16132 Genova,undefined
[7] Italy e-mail: derchi@unige.it Tel.: + 39-0 10-3 53 72 34 Fax: 39–010–3537213,undefined
[8] Ospedale San Luca,undefined
[9] IRCCS,undefined
[10] Istituto Auxologico Italiano,undefined
[11] 20149 Milan,undefined
[12] Italy,undefined