1 Department of Medical and Pediatric Sciences, Diagnostic and Therapeutic Unit, University of Catania, Catania, Italy. E-mail: guglielmotrovato@unict.it.
2 Department of Internal Medicine, Diagnostic and Interventional Ultrasound Unit, Istituto di Ricovero e Cura a Carattere Scientifico, Casa Sollievo della Sofferenza Hospital, San Giovanni Rotondo, Italy.