脑蛛网膜下腔出血 (ＳＡＨ)是临床上一种较常见的脑血管疾病 ,该病的预后一般较好 ,但有部分病人出现一些并发症 ,如 :再次出血、脑积水、脑血管痉挛等 ,一旦出现上述并发症 ,则预后差。因此这些并发症的早期识别 ,对治疗ＳＡＨ至关重要。经颅多普勒超声对脑血管的诊断较敏感 , Subarachnoid hemorrhage (SAH) is a relatively common cerebrovascular disease in the clinic. The prognosis is generally good, but some patients have some complications such as rebleeding, hydrocephalus, cerebral vasospasm And so on, in the event of the above complications, the prognosis is poor. Therefore, the early identification of these complications is crucial for the treatment of SAH. Transcranial Doppler ultrasound is more sensitive to the diagnosis of cerebrovascular disease,