1. A schematic diagram demonstrating the measurement of the degree of circumferential contact between ICA and the tumor.
A schematic diagram demonstrating the measurement of the degree of circumferential contact between ICA and the tumor. Two intersecting lines are drawn between the center of ICA and the points of contact of the circumference of the vessel with the edges of the tumor to obtain the angle (A). A, Type I tumor: the angle “A” is depicted between the 2 intersecting lines. B, Type II and III tumors: the angle measurement tool automatically measures the smaller angle (less than 180°) between the intersecting lines. The actual angle A is the difference between 360° and measured angle “a” (360°−a), as shown here.
S. Arya et al. AJNR Am J Neuroradiol 2008;29:
©2008 by American Society of Neuroradiology