Objective:To evaluate the feasibility and usefulness of 3D time of flight MR angiography(TOF-MRA) for the follow-up of intracranial aneurysms treated with guglielmi detachable coils. Methods:Total of 38 patients with 38 aneurysms treated with guglielmi detachable coils over 36 months were examed by 3D TOF-MRA and DSA simultaneously. DSA was the reference for the detection of a residual neck or residual aneurysm. Recurrence of aneurysms and patency of parent arteries were determined by comparing MRA with DSA. Results:In 38 aneurysms,DSA found that 33 cases were stable,and 5 were recurrent. Meanwhile,36 parent arteries were patent,and the others were occluded by DSA. MRA found that 32 were stable,and 6 were recurrent,and 34 parent arteries were patent,and 4 were occluded. The sensitive and specificity to diagnose residual flow by MRA were 84.6% and 92.0%,respectively;the sensitive and specificity of MRA to diagnose recurrence were 80.0% and 93.0%,respectively;the sensitive and specificity of MRA to diagnose that whether parent arteries is patent or not were 94.4% and 100%,respectively. Conclusions:3D TOF-MRA is efficient and reliable for the long term follow-up of intracranial aneurysms. Moreover,further experimental evidence of MRA is needed.