Comparison of MRA and angiography in the follow-tip of intracranial aneurysms treated with GDC. Report of 25 correlations

Objective: Evaluation of TOF 3D MRA compared to angiography in the follow-z ip of intracranial aneurysms treated by Guglielmi detachable coils (GDC). Material and method: Prospective analysis of follow-up MRA and angiographie s for 20 patients with 22 aneurysms. There were 2 MRAs for 3 aneurysms givi ng a total of 25 cases. Results: A poor correlation between MRA and angiography was observed in 21 cases of 25. For 9 cases, stable exclusion (95-100%) visible on MRA was con firmed by angiography. For 12 other cases, a residual flow within the aneur ysmal neck or a residual flow between coils was detected by MRA and confirm ed by angiography. A poor correlation was found in 4 cases out of 25: 3 res idual flows within the aneurysmal neck and I residual flow within the coil mass not visible on MRA. MRA has a sensibility of 75% for the detection of an anomaly, a specificity of 100%, a positive predictive value of 100% and a negative predictive value of 69.2%. MRA is able to detect a large residua l flow within aneurysmal neck and a re-growth, wich would need a second emb olization. Anomalies not visible on MRA as observed in our study, residual flow within the coil mass and the aneurysmal neck, do not require complemen tary treatment. Conclusion: A normal TOF 3D MRA can avoid an angiography in the follow-zip of an intracranial aneurysm treated by GDC.