Gated Multidetector Computed Tomography

Abstract

Streak artifacts caused by aneurysm clips and coils impede image quality in multidetector computed tomography (MDCT). The authors propose a technique to minimize these artifacts by gated data reconstruction and shifting the reconstruction window. Intracranial CT angiograms were acquired in the follow-up of six patients with clipped and coiled intracranial aneurysms, respectively. Images were reconstructed from four consecutive 45 degrees rotated segments with an acquisition time of 52.5 ms/segment. Data acquisition was gated via an external pacemaker cable-connected to the scanner. Artifact orientation could be rotated by shifting the reconstruction window and interesting vessel segments visualized without disturbing streak artifacts. This allowed to assess the posterior communicating artery origin in two cases and a middle cerebral artery aneurysm remnant in another case, respectively. However, due to a higher noise interesting vessel segments were not adjustable in another three patients. Gated MDCT is a promising technique to reduce the amount and to change the position of artifacts induced by clips or coils.