MRA is useful as a follow-up technique after endovascular repair of aortic aneurysms with nitinol endoprostheses

PURPOSE: To evaluate whether MR angiography (MRA) is a useful tool for the follow-up of aortic aneurysms treated with nitinol endoluminal grafts. MATERIALS AND METHODS: We examined 28 patients treated with nitinol endovascular stents to repair an aortic aneurysm with CT angiography (CTA) and MRA. Eleven patients (group 1) underwent an MRA after a positive CTA for endoleak was observed. Afterwards, 17 patients (group 2) were scheduled for both follow-up examinations. The kind of endoleak that occurred and the maximum aortic diameter were compared. The sensitivity of CTA relative to MRA for detecting endoleaks in group 2 was calculated. Signal-to-noise ratios (SNRs) were measured in the aortoiliac lumen at the arterial phase in, above, and below the endoprostheses. Student's t-test was used to compare aneurysm dimensions and SNR measurements. RESULTS: Three type III leaks were correctly assessed at both examinations; however, CTA was less sensitive (50%) than MRA in depicting type II or unclassified leaks. No differences in aneurismal size were observed between the two examinations or between arterial SNRs observed in or out of the devices. CONCLUSION: MRA can provide all relevant information necessary for the follow-up of patients treated with nitinol endoprostheses, and performs better than CTA in detecting endoleaks.