Three-dimensional time-of-flight MR angiography in the evaluation of intracranial aneurysms treated with Guglielmi detachable coils

BACKGROUND AND PURPOSE: Intravascular treatment of intracranial aneurysms i s a relatively new therapeutic technique and long-term controlled angiograp hic trials are needed to assess persistence of aneurysm occlusion, Our purp ose was to evaluate the effectiveness of 3D time-of-flight (3D-TOF) MR angi ography as a noninvasive screening tool in the follow-up of cerebral aneury sms treated with Guglielmi detachable coils (GDCs), METHODS: Forty-nine patients with 50 intracranial aneurysms previously trea ted with GDCs were studied with both DSA and 3D-TOF MR angiography, In 14 c ases, a second followup examination was performed, for a total of 64 aneury sms evaluated. In 25 aneurysms, both pre- and postcontrast MR angiographic studies were obtained, RESULTS: In seven of 64 aneurysms, the MR angiographic studies were conside red to be unreliable owing to the presence of artifacts that obscured part of the parent artery and did not allow an accurate evaluation of the aneury sm neck. These seven aneurysms, however, all were shown to be completely oc cluded at digital subtraction angiography (DSA), In the remaining 57 aneury sms, DSA revealed complete occlusion in 39 and the presence of residual pat ency in 18, whereas MR angiography showed complete occlusion in 38 and resi dual patency in 19, Enhanced MR angiography proved to be useful in evaluati ng residual patency in large and giant aneurysms and in better depicting th e distal branch arteries, CONCLUSION: Although artifacts related to the presence of coils are evident on a considerable number of imaging studies, our findings indicate that MR angiography is useful in the evaluation of residual patency of cerebral an eurysms treated with GDCs and may eventually prove valuable in the follow-u p of those cases in which a good initial correlation with DSA was demonstra ted.