Evaluation of contrast-enhanced MR angiography in the follow-up of visceral arterial aneurysms after coil embolization

Abstract

Background The placement of detachable coil has become the alternative method of treating visceral arterial aneurysms (VAAs). Imaging follow-up is necessary after coil embolization because of frequent incomplete occlusion. Purpose To compare contrast-enhanced magnetic resonance angiography (CE-MRA) at 3T with a reference standard of digital subtraction angiography (DSA) for the evaluation of VAAs after coil embolization. Material and Methods We treated 15 patients with VAA with coil embolization; eight had splenic artery aneurysms and seven had renal artery aneurysms. We packed the aneurysmal sac preserving native arterial circulation. For follow-up, all patients underwent CE-MRA at 3T and DSA. The results were classified according to coil occlusion: Class 1, complete occlusion; Class 2, residual neck; Class 3, aneurysmal filling. Results CE-MRA revealed 11 complete occlusions and four residual necks. DSA follow-up showed 12 complete occlusions and three residual necks. No aneurysmal filling occurred after treatment. Comparison of CE-MRA and DSA findings showed 93% agreement (14/15). CE-MRA allowed the detection of a residual neck in one misclassified case in which DSA showed occlusion. Coil-related artifacts were minimal and did not interfere with evaluation of the occlusion status of the VAAs. Conclusion CE-MRA at 3T provides high-quality images equivalent to DSA for the evaluation of VAAs after coil embolization. We suggest that CE-MRA at 3T might be used as the primary method for follow-up of VAAs after coil embolization.