Analysis and Diagnosis of Abnormal Flow Velocity and Spectralvien of Intracranial Vertebral Artery

Objective To explore the pattern,lesion position and cause of abnormal blood flow of intracranial vertebral artery.Methods In 299 patients with severe stenosis or occlusion of intracranial or extracranial artery determined by MR angiography and/or digital subtraction,the abnormal blood flow of intracranial vertebral artery was evaluated with transcranial Doppler(TCD) and cervical continuous-wave Doppler(CWD).Results In 299 patients,598 intracranial vertebral arteries were evaluated.Five hundred and eight arteries showed abnormal flow that manifested stenosis flow(32 arteries),absent flow(17 arteries),low velocity and pulsitility(58 arteries),low velocity and high pulsitility(42 arteries),compensatory flow(287 arteries) and steal spectral(72 arteries).The stenosis flow or absent flow was discovered directly in lesion position.However,other 4 patterns of abnormal blood flow resulted from indirect flow change of proximal or distal artery of lesion position.Conclusions To evaluate the abnormal blood flow of intracranial vertebral artery with TCD and CWD might provide important and objective basis in discovering the cause of posterior circulation ischemia and in exploring deeply the pathogenesis of ischemic cerebrovascular disease.