Figure 2From: A 3D numerical study of the collateral capacity of the circle of Willis with anatomical variation in the posterior circulationAnatomical variations of the CoW. The black arrows point out the variant arteries compared with the normal CoW model. (a) normal-type circle or NT; (b) fetal-type posterior or FTP; (c) transitional-type or TransT; (d) full FTP or fuFTP; (e) bilateral FTP or bFTP; (f) bilateral PCoA hypoplasia or bhypPCoA; (g) unilateral PCoA hypoplasia or uhypPCoA; (h) unilateral PCoA absent or uabPCoA.Back to article page