Fig. 2From: The classification of intracranial aneurysm neck: a single center research experienceAneurysm neck surface occupies the size of the perimeter of the responsible vessels (A, B): 2.1 A type (the neck surface is less than the 1/2 of the tumor artery circumference), and the 2.2 B type (the tumor neck surface is smaller than the 1/2 of the tumor artery circumference)Back to article page