Intracranial aneurysms: evaluation in 200 patients with spiral CT angiography

The goal of this study was to assess the usefulness of spiral CT angiograph y (CTA) with three- dimensional reconstructions in defining intracranial an eurysms, particularly around the Circle of Willis. Two hundred consecutive patients with angiographic and/or surgical correlation were studied between 1993 and 1998, with CTA performed on a GE HiSpeed unit and Windows worksta tion. The following clinical situations were evaluated: conventional CT sus picion of an aneurysm; follow-up of treated aneurysm remnants or of untreat ed aneurysms; subarachnoid haemorrhage (SAH) and negative angiography; fami ly or past aneurysm history; and for improved definition of aneurysm anatom y. Spiral CTA detected 140 of 144 aneurysms, and an overall sensitivity of 97 %, including 30 of 32 aneurysms 3 mm or less in size. In 38 patients wit h SAH and negative angiography, CTA found six of the seven aneurysms finall y diagnosed. There was no significant artefact in 17 of 23 patients (74 %) with clips. The specificity of CTA was 86 % with 8 false-positive cases. Sp iral CTA is very useful in demonstrating intracranial aneurysms.