Figure 1: First and second image reveals approach to interoptic cisterns. Third and forth image shows optic chiasma and interoptic cisterns. After that, the opticocarotid cistern is opened in a sharp fashion. The lateral carotid cistern between the carotid and the third nerve is also opened. Through either one of these cisterns, the membrane of Liliequist is opened and the basilar, bilateral PCAs, superior cerebellar arteries and the third nerve is visualized