[1] CIBER BBN, Cardiovasc Res Ctr, CSIC ICCC, Barcelona, Spain
[2] Hosp Univ Germans & Trias Pujol, Serv Cardiol, Badalona, Spain
[3] Hosp Santa Creu & Sant Pau, Neurosurg Unit, Barcelona, Spain
[4] Stanford Univ, Dept Radiol, Bio X Program, Stanford, CA 94305 USA