Diagnostic imaging in neurovascular surgery: Will CT-angiography replace digital substraction angiography?

Introduction: The “gold standard” in assessing number, configuration and blood supply pattern in cerebral aneurysm is digital substraction angiography (DSA) at present. Methods: We conducted a retrospective study of 50 patients with CT proven subarachnoidal hemorrhage (SAH) in our department to compare CT-angiography and DSA with regard to aneurysm detection, flow patterns and morphological appearance. All cases within a one year period were included (X/95-X/96). Particular attention was drawn to the morphological appearance and flow patterns of partially or totally thrombosed aneurysms. Results: All aneurysms of anterior and posterior circulation could be clearly identified on CT-Angiography. On DSA however, one aneurysm could not be identified, the CTA clearly showing the aneurysm origin. By rotating the CTA-images in 3-D-mode, all necks could be identified and measured in the respective plane. Conclusion: With false negative imaging in 2.5% in the actual series and a potentially higher complication rate by intraarterial contrast application, DSA seems inferior to CTA related to the preoperative workup of patients with cerebral aneurysms. In our view, CTA will replace DSA in most vascular imaging procedures in the near future.