[1] Pontificia Univ Catolica Rio Grande do Sul, Dept Radiol, Hosp Sao Lucas, Ave Ipiranga, Porto Alegre, RS, Brazil
[2] Univ Florida, Coll Med, Dept Radiol, Gainesville, FL 32610 USA
[3] Rio Preto Radiodiagnost Intitute R Cila, Dept Radiol, Sao Jose Do Rio Preto, Brazil
[4] Univ Fed Rio de Janeiro, Dept Radiol, Ave Carlos Chagas Filho, Rio De Janeiro, Brazil
[5] Massachusetts Gen Hosp, Dept Radiol, Div Thorac Imaging & Intervent, Boston, MA USA
[6] Harvard Med Sch, Founders House, Boston, MA 02115 USA