Intraoperative angiography is done in the operating room during a surgical procedure of the brain. One common situation is when a brain aneurysm is clipped. The intraoperative angiogram is done to make sure that the aneurysm clip is correctly placed. If there is still a residual aneurysm the clip can be adjusted or another clip can be placed. In the situation where an adjacent vessel has been compromised the clip this can also be adjusted.