Normal Anatomical Features and Variations of the Vertebrobasilar Circulation and Its Branches: An Analysis with 64-Detector Row CT and 3T MR Angiographies

Table 1

Diameters of the branches of vertebrobasilar circulation.

	Artery (mean diameter ± SD mm)
	VA	PICA	AICA	SCA	PCA
Right	2.95±0.47	1.67±0.45	1.24±0.38	1.59±0.39	2.56±0.43
Left	3.23±0.57	1.64±0.37	1.28±0.42	1.52±0.31	2.43±0.34
Total	3.08±0.53	1.66±0.53	1.26±0.43	1.56±0.44	2.52±0.36

VA: vertebral artery, PICA: posterior inferior cerebellar artery, AICA: anterior inferior cerebellar artery, SCA: superior cerebellar artery, and PCA: posterior cerebral artery.