2Hoshino A. Report on the safety of unil atreal artery ligation during cervical spnie surgery[J ]. Spine, 1996,21 : 1454.
3Bradley WG. MR of the brain stem: a pracfical approach[J ]. Rodiology, 1991,179 : 319.
4Seidelm E, Eicke BM, Tettenbom B, et al. Reference ralues for vertebral arfery flow volume by duples sonograpluy in young and elderly adults[ J ]. Stroke, 1999,30:2692.
6Bray J M, Missoum A, Dubas F, et al. Detection of Vertebrobasilar intrac raninl steonses:transcranial Doppler sonog raphy versus angiog-raphy[J] .J Transound Med, 1997,16(3) :213.
7Magarelli IV ,Scarabino T ,Sineone AL, at al. Carotid stenosis: A comparision betm MR and spinal CT anyiography[J ] .Neuroradiology, 1998,40 : 367.
8Seemann MD, Englmeiev K, Schuhm DK, et al. Evaluation of the carotid and vertebral arteries,comparison of 3D SCTA and IADSA work in progress[J ]. Europe Radiology, 1999,9 : 1105.
