Aneurysmal subarachnoid hemorrhage: imaging strategies and cost-effectiveness aspects in diagnostic work-up and post-therapeutic follow-up

Background and purpose: Most centers use computed tomographic angiography (CTA) as the primary diagnostic tool in patients presenting with a subarachnoid hemorrhage (SAH). Contrast enhanced magnetic resonance angiography (CEMRA) might be an alternative technique. In this study the ability to detect cerebral aneurysms with CEMRA in patients presenting with a SAH is investigated and compared with CTA. Methods: In 75 consecutive patients, two experienced neuroradiologists evaluated CEMRA and CTA images. Digital Subtraction Angiography (DSA) served as standard of reference. The diagnostic performance in detection of aneurysms, in terms of sensitivity, specificity and interobserver variability, was calculated for both modalities and a comparison was made between the two. Results: No significant difference was found between the two modalities for the detection of aneurysms: sensitivities for the two observers were 96.6 and 93.8 respectively for CEMRA and 90.8 and 92.3 for CTA; specificities were 77.8 and 88.9 for CEMRA and 94.4 in both observers for CTA. Kappa values for interobserver variability were 0.82 for CEMRA and 0.85 for CTA. Conclusion: The diagnostic accuracy of CEMRA and CTA in the work-up of patients presenting with a SAH does not differ significantly. The choice to use either CEMRA or CTA depends on preference or availability.