Intracranial aneurysms treated with Guglielmi detachable coils - Imaging follow-up with contrast-enhanced MR Angiography

Background and Purpose - To compare the utility of contrast-enhanced MR Angiography (CE-MRA) with digital subtraction angiography (DSA) after endovascular treatment of intracranial aneurysms with Guglielmi detachable coils. Methods - From April 1999 to August 2002, 106 patients with 107 aneurysms treated by endovascular coiling using Guglielmi detachable coils underwent simultaneous DSA and CE-MRA at follow-up ( mean: 12.9 range: 5 to 27 months). DSA was performed as the standard reference. MR angiographic images were analyzed independently by 2 senior radiologists (J.-Y.G., S. C.) and DSA by a third radiologist ( X. L.). Findings were assigned to 1 of 3 categories: complete obliteration ( class 1), residual neck ( class 2) and residual aneurysm ( class 3). Results - DSA at follow-up demonstrated 65 (60.6%) complete obliterations ( group 1), 21 (19.7%) residual necks ( group 2) and 21 ( 19.7%) residual aneurysms ( group 3). One patient (0.9%) experienced aneurysm rebleed during the follow-up period. Among 101 assessable imaging comparisons, interobserver agreement was determined to be very good for CE-MRA ( kappa = 0.96) with only 4 discrepancies between both examiners. Comparison between CE-MRA and DSA showed an excellent agreement between techniques (kappa = 0.93). Of the 21 with residual necks described on DSA, 20 were seen on CE-MRA. CE-MRA detected all 19 residual aneurysms. Conclusion - CE-MRA after selective embolization of intracranial aneurysm is useful and comparable to DSA in the assessment of aneurysmal recanalization either as residual neck or aneurysmal sac.