1 Diagnostic and Interventional Ultrasound Unit, Valle del Serchio General Hospital, Lucca, Italy.
2 Pulmonary Medicine Unit, Department of Cardiovascular and Thoracic Sciences, Fondazione Policlinico Universitario Agostino Gemelli, Istituto di Ricovero e Cura a Carattere Scientifico, Rome, Italy.
3 Department of Woman and Child Health and Public Health, Fondazione Policlinico Universitario Agostino Gemelli, Istituto di Ricovero e Cura a Carattere Scientifico, Rome, Italy.
4 Emergency Department, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Policlinico San Matteo, and Department of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy.
5 Bresciamed, Brescia, Italy.
6 7118 USL Nordovest Toscana, Lucca, Italy.
7 Emergency Medicine Unit, General Hospital, Voghera, Italy.
8 Pulmonary Medicine Unit, Lodi General Hospital, Lodi, Italy.
9 Department of Information Engineering and Computer Science, Ultrasound Laboratory Trento, University of Trento, Trento, Italy.