Fig 4.

A, 3D volume reformat of CTA demonstrates a bilobed anterior communicating aneurysm. B, Axial MPR image obtained in the perioperative period demonstrates a round contrast collection consistent with a residual aneurysm remnant (arrow) of the posterior lobe of the bilobed aneurysm. C, Sagittal reformat also demonstrates a similar finding (arrow) and better shows the relation to the aneurysm clips. D, 3D volume rendering of the same CTA data, viewed from the anterior and below, gives an easily identifiable angiographic appearance that shows the residual aneurysm remnant (arrow) and the relation to the parent vessel and clips. E, Follow-up angiogram of the right internal carotid artery obtained 1 week post-subarachnoid hemorrhage demonstrates the residual aneurysm lumen (arrow) as well as a vasospasm involving the supraclinoid internal carotid artery and A1 segment. F, After coil embolization of the aneurysm remnant (arrow), the angiogram shows no residual aneurysm.