Chae et al. right and head-to-foot rotation. Aneurysm outcome was classified as same as the DSA. An aneurysm was consid- ered to be recurrent when a previously adequately occluded aneurysm was found to have partial or even less recanalization of the neck and sac. RESULTS Angiographic Outcome Immediate aneurysmal occlusion was adequate in 25 (81%) aneurysms (5 out of 5 ruptured aneurysms, 100%; 20 out of 26 unruptured aneurysms, 77%), and incomplete in six (19%) aneurysms. For the six aneurysms with an incomplete occlusion, additional treatments were not performed because all six aneurysms were unruptured and the remnants of aneurysmal sac were not large enough to require additional retreatment. The count of used coils ranged from 1 to 5 (mean count, 2.4) and the mean packing density was 34%. Procedural Complications Two thromboembolic complications (7%) occurred A B C D Fig. 1. Follow-up MR angiographic images in ages in 61-year-old woman. A. Roadmap image shows that microcatheter tip is in aneurysm on top of basilar artery. Another small aneurysm is noted between basilar artery and left superior cerebellar artery. B. Postembolization angiography shows contrast filling of residual aneurysmal sac, especially in dome of aneurysm. C. Source image of 3D TOF MRA on day following coil embolization depicts focal high signal intensity, thus suggesting residual arterial flow in embolized aneurysm (arrow). D. Source image of six month follow-up 3D TOF MRA shows loss of high signal intensity in embolized aneurysm (arrow). 538 Korean J Radiol 11(5), Sep/Oct 2010