Circulus arteriosus cerebri

例句：

1. 1.The patient was diagnosed with a brain aneurysm, which required immediate surgery.
   患者被诊断出患有脑动脉瘤，需要立即进行手术。
2. 2.The study found that the Circulus arteriosus cerebri plays a crucial role in blood flow regulation.
   研究发现，大脑动脉环在血流调节中起着至关重要的作用。
3. 3. The doctors performed a successful operation to repair the damaged Circulus arteriosus cerebri.
   医生们成功地进行了一次手术，修复了受损的大脑动脉环。