FIG 3. Signal intensity void in parent artery and susceptibility artifact immediately after coil placement.

A, DSA shows an aneurysm at basilar artery–superior cerebellar artery bifurcation at the end of coil placement. Neck remnant (arrowhead) and protrusion of a coil into the basilar artery (arrow) are observed.

B, Targeted MIP of MRA image obtained 3 days after coil placement shows neck remnant more clearly than does DSA image (arrowhead). Signal intensity loss in the basilar artery (arrow) is due to coil protrusion. Signal intensity loss in left posterior cerebral artery (asterisk) is due to susceptibility artifact of the clip in another aneurysm at the left internal carotid–posterior communicating artery bifurcation.