Figure 4. Digital subtraction angiography demonstrating a right-sided PPOA (red arrow) with an associated aneurysm (red star) (left). The distal PPOA supplies the frontal lobe. Computed tomography angiography demonstrating a PPOA (red arrow) with an associated aneurysm (right). The vessel runs along the olfactory tract of the gyrus rectus and connects with the distal ACA.