Fig 4. Type II CBT. A, Axial T2-weighted MR image showing a type II right-sided carotid body tumor (star) splaying the ICA posteriorly and ECA (arrow) anteriorly. The circumferential degree of contact of the tumor with the ICA is the difference between 360° and the measured angle (150°) in the figure, that is, 210°. B, Line diagram illustrating the tumor-ICA circumference of contact of the type II CBT in A.