1 Diagnostic and Interventional Radiology, IRCCS Istituto Ortopedico Rizzoli, Via G. C. Pupilli 1, 40136 Bologna, Italy. Electronic address: abazzo@inwind.it.
2 Department of Radiology, University of Foggia, Viale L. Pinto 1, 71100 Foggia, Italy. Electronic address: giuseppe.guglielmi@unifg.it.