The value of computed tomography angiography in determining treatment allocation for aneurysmal subarachnoid hemorrhage

Background and Purpose: Computed tomography (CT) and CT angiography (CTA) are frequently the initial imaging modalities used in the evaluation of patients with suspected aneurysmal subarachnoid hemorrhage (SAH). It remains unclear whether CTA can provide adequate information to determine best treatment modality (endovascular versus surgical) for ruptured intracranial aneurysms. Methods: Pertinent clinical and radiological information of consecutive patients with aneurysmal SAH who underwent CTA on a 64-slice multidetector CT (MDCT) scanner were independently reviewed by five endovascular specialists. Subsequently, the interobserver reliability was calculated. Results: A total of 21 consecutive patients with aneurysmal SAH detected on CTA were reviewed. Of the total of 105 reviews, in 65% a treatment allocation decision was made. Responses were, 26% either treatment; 18% endovascular only; 18% surgical only; and 3% neither treatment. In the remaining 35% it was considered that CTA images were inadequate to make a decision for treatment allocation and more information was requested. Interobserver reliability was poor between endovascular specialists (k = 0.2). The reliability was higher among endovascular/vascular neurosurgeons (k = 0.34) and physicians with >5 years of faculty experience (k = 0.55). Conclusion: When 64-slice MDCT angiography is used in the evaluation of aneurysmal SAH, the information obtained is adequate to determine treatment modality allocation in two-thirds of the cases. The agreement on best treatment modality varied across primary specialty, practice experience, and site of fellowship completion.