Objective:To investigate the effect of the aneurysm clip on the CTA image after clipping of intracranial aneurysm. Methods:Arteries of ruptured aneurysms and aneurysm clips imaging from 62 patients undergoing head subtraction CTA examination were retrospectively reconstructed

and the volume rendering(VR)and multiplanar reconstruction(MPR)were used to evaluate the effect of aneurysm clips and the accuracy of VR and MPR in the patients with aneurysm clipped

as well as to observe the residual aneurysms after clip. Results:CTA can clearly show the relationship between the aneurysm clip and the carrying vessel. Kappa index of agreement:K=0.452 was used for the conventional VR and the MPR(P=0.000)and K=0.132 for the MPR and the subtraction VR(P=0.019).Consistency was observed between conventional VR

MPR and vascular stenosis evaluation while poor consistency was observed between MPR and the subtraction VR. Aneurysm clip artifact was divided into 3 grades:type a 49 cases(79.0%)

type b 11 cases(17.7%)

type c 2 cases(3.2%). The rank sum test of the number of clips and clip artifact contrast show that the results were not statistically different(P >0.05). Conclusion: CTA image quality is affected by the metal artifact and the shadow of the clip. We should combine subtraction CTA with multi type image reconstruction methods to improve the accuracy of the treatment for patients after aneurysm clipping.