Effectiveness of MRA on embolized intracranial aneurysms: a comparison of DSA, CE-MRA, and TOF-MRA

Purpose: The endovascular treatment of intracranial aneurysms was proven safe and effective compared to the alternative method of surgical clipping, despite the high recurrence rate. Follow-up of embolized intracranial aneurysms is mandatory for the early detection of recurrence and improved outcomes. DSA is used as the reference standard for this assessment. To determine the effectiveness of MRA in follow-up evaluations of intracranial aneurysms after embolization by comparing DSA, CE-MRA, and TOF-MRA. Materials and Methods: Sixty-eight consecutive patients undergoing DSA, TOF-MRA, and CE-MRA during an interval of <1 week were enrolled in this 6-month study. Images were evaluated for occlusion status, patency of the parent vessels, and artifacts. The modified Raymond-Roy occlusion classification and Aneurysm Embolization Grades were used to assess the occlusion status and initial DSA images for detection of recurrence in two filtered study phases with optimized selection criteria. Seventeen observers (phase I: 9, phase II: 8) independently interpreted the double-blinded images. Agreement was expressed with a Fleiss kappa value; p < 0.05 was considered significant. Results: This study included 68 patients with 77 aneurysms; 38 (49.35%) were treated with coil alone and 39 (50.65%) with stent-assisted coiling. In both phases, DSA was superior to TOF-MRA and CE-MRA using MRRC (Phase I: k = 0.567, p ≤ 0.001; k = 0.287, p ≤ 0.001; k = 0.117, p ≤ 0.001, respectively; Phase II: k = 0.503, p ≤ 0.001; k = 0.303, p ≤ 0.001; k = 0.115, p = 0.038, respectively). TOF-MRA was as effective as DSA (TOF: k = 0.335, p ≤ 0.001; DSA: k = 0.323, p ≤ 0.001) for recurrence detection. Conclusion: We suggest TOF-MRA as a first-line follow-up tool to detect aneurysm recurrence, and DSA to quantify the filling space to make a definite decision on re-embolization.