[1] UNIV CALIF SAN FRANCISCO,DEPT RADIOL,SAN FRANCISCO,CA 94143
[2] HOP PURPAN,NEURORADIOL SERV,TOULOUSE,FRANCE
[3] UNIV CALIF SAN FRANCISCO,DEPT NEUROSURG,SAN FRANCISCO,CA 94143
[4] VET ADM MED CTR,DEPT NEUROSURG,SAN FRANCISCO,CA 94121
[5] UNIV TORONTO,DEPT RADIOL,TORONTO M5S 1A1,ONTARIO,CANADA