[1] Hosp Sirio Libanes, Res & Educ Inst, Sao Paulo, Brazil
[2] Univ Sao Paulo, Hosp Clin, Inst Canc, Dept Radiol, Sao Paulo, Brazil
[3] Univ Zurich, Univ Zurich Hosp, Dept Med Radiol, Div Nucl Med, CH-8091 Zurich, Switzerland
[4] Univ Zurich, Univ Zurich Hosp, Div Neuroradiol, CH-8091 Zurich, Switzerland