MR angiography of saccular aneurysms after treatment with Guglielmi detachable coils: preliminary experience.

PURPOSE: To review our experience using MR angiography to assess the cerebral vasculature after aneurysmal treatment with Guglielmi detachable coils (GDCs). METHODS: Forty three-dimensional time-of-flight MR angiographic studies were performed in 23 patients after endovascular aneurysmal therapy with GDCs. Digital subtraction angiographic (DSA) studies were evaluated retrospectively for the following findings: parent artery patency, branch vessel patency, residual flow within the aneurysm, and residual aneurysmal neck. The MR angiographic examinations were inspected for the same findings, as well as for the degree of signal loss surrounding the coil mass. Clinical histories were reviewed to determine the impact of MR angiographic findings on therapy. RESULTS: Patency status of the parent artery was correctly identified on 25 of 26 MR angiographic examinations with DSA confirmation. Thirty-four of 37 patent branch vessels were identified by MR angiography. Residual neck was correctly identified in seven studies of six aneurysms, with no false-negative or false-positive results. Intraaneurysmal flow was correctly identified in five of eight studies of six aneurysms with residual flow shown by DSA. Artifact and hemorrhage mimicked residual flow in two of 18 MR angiographic studies of aneurysms with no residual flow shown by DSA. In eight patients, MR angiography provided clinically useful information that affected therapy. CONCLUSIONS: MR angiography can identify flow within an aneurysm after treatment with GDCs as well as in the adjacent parent and branch vessels. This technique may be a useful adjunct to DSA in some clinical situations.