Objective:To explore of clinical value of three-dimensional computed tomography angiography(3D-CTA) in the etiological diagnosis and management of intracranial aneurysm.Methods:One hundred and fifteen patients with spontaneous SAH admitted from September 2007 to August 2008 were examined with 3D-CTA

and were examined with digital subtracted angiography(DSA)

and eighty nine patients were found suffering from intracranial aneurysm which underwent DSA.Repeated 3D-CTA was performed 1 week after clipping in eighty one patients or embolization in eignt cases.The findings of 3D-CTA were compared with the results of DSA.Results:A total of ninty seven aneurysms in eighty nine cases were detected by 3D-CTA

but DSA revealed ninty three anurysms.DSA confirmed the findings of CTA except for five cases of small anterior communicating aneurysms and three cases posterior communicating aneurysms which were demonstrated by 3D-CTA and verified by surgery but missed by DSA and four cases which were found by DSA and verified by surgery but missed by 3D-CTA.The sensitivity of 3D-CTA to diagnose the intracranial aneurysms is 95.6% and the specificity is 100% and the accuracy is 96%.The diagnose accordance rate among 3D-CTA and DSA and/or surgery is 88.1%.Conclusion:3D-CTA and 2D-DSA and/or surgery have high diagnose accordance rate

and we should combine the two diagnostic techniques to examine intracranial aneurysms accurately.