Anterior part of ambient cistern mainly contained anterior choroidal artery,basal vein of Rosenthal and P2segment of posterior cerebral artery. The fibrous trabeculae were not much in the cistern. Most trabeculae were scatter and short.

• 环池前部主要含有脉络膜前动脉、基底静脉及大脑后动脉P2段,纤维小梁不多,多为散在的短纤维。