Abnormal of the vertebral artery on MR:ever-present imaging change of top of the basilar syndrome

Objective:Observe the vertebral and basilar artery on MR imagining in patients suffering top of the basilar artery syndrome(TOBS). Discuss the mechanism of TOBS. Methods: Retrospectively study all patients underwent MRI examination from 1998 to 2005. Observe the flow void of vertebral and basilar artery,normal or abnormal flow void of the artery were noticed. Results:There were 31 patients fulfilling the demands. Among them,abnormal flow void of vertebral or basilar arteries was noticed in 25 cases(80.6%),unilateral vertebral artery involved in 17 cases(54.8%),both vertebral and basilar artery involved in 6 cases(19.4%),only basilar artery involved in 2 cases(6.5%),normal flow void was noticed in 6 cases(19.4%).Conclusions:Abnormal flow void of vertebral or basilar artery often exist in patients with TOBS. Unilaterel vertebral artery involved more often. This indicates that artery_artery embolism may play an important role in TOBS.