Nonhelical Acquisition CT Angiogram After Aneurysmal Clipping: In Vitro Testing Shows Diminished Artifact

SUMMARY: Imaging of the cerebral vessels with use of CT angiogram (CTA) after placement of aneurysmal clips is often limited by clip artifacts. We used a phantom to demonstrate a visible reduction in metal artifact when using the axial technique, compared with the usual CTA helical acquisition. This approach may have some advantage when used for CTA with 64-section scanners in the specific circumstance of immediate postoperative imaging after placement of cerebral aneurysmal clips. CT angiogram (CTA) is an attractive alternative for patientswho require imaging of the cerebral vasculature after an-eurysm clipping compared with conventional angiography. Although advances in CT technology and the use of titanium clips have improved the quality of CTA after aneurysmal clip-ping, artifacts arising from the clip limit the visualization of the aneurysmal neck and nearby vessels in some cases.1 CTA usually requires the use of helical image acquisition, to provide rapid imaging with sufficient coverage, but it is of interest to consider thatCT imaging of the brain atmost sites is donewit