Figure 1:

Preoperative images. (a) MR diffusion weighted images at presentation demonstrated cerebral infarction at right basal ganglia and corona radiata. (b) T2 weighted image-vessel wall MR showed aneurysm with partial thrombosis (30.57 mm) and enhancement of superior aspect. (c) Digital subtracted angiography confirmed a large saccular aneurysm (14.9 × 26.1 mm) at the right middle cerebral artery. (d) After early bifurcation of middle cerebral artery, the aneurysm was originated from the frontal branch. Superior and inferior divisions of frontal branch are branching out from the aneurysm dome. (arrows) (inlet).