1. Faculty of Medicine, Pontificial Catholic University of Rio Grande do Sul, Av. Ipiranga 6690, Porto Alegre 90619-900, Brazil
2. Department of Nuclear Medicine, Hospital Mae de Deus, Av. Jose de Alencar 286, Porto Alegre 90880-481, Brazil
3. Graduate Program in Pathology, Federal University of Health Sciences of Porto Alegre, Rua Sarmento Leite 245, Porto Alegre 90050-170, Brazil
4. School of Medicine, Federal University of Rio Grande do Sul, R. Ramiro Barcelos, 2400—Santa Cecília, Porto Alegre 90035-003, Brazil