Utility of CT angiography and MR angiography for the follow-up of experimental aneurysms treated with stents or Guglielmi detachable coils

BACKGROUND AND PURPOSE: Previous studies have depicted arterial and aneurys mal anatomy with three-dimensional time-of-flight (3D-TOF) MR angiography b efore and after treatment with Guglielmi detachable coils (GDCs) and with C T angiography before and after treatment with stents and stent-grafts, We i nvestigated the ability of time-resolved contrast-enhanced SD MR angiograph y (3D MR digital subtraction angiography [DSA]) to accurately depict the an atomy of experimental lateral aneurysms before and after treatment with GDC s and a variety of stents or stent-grafts, and compared these findings with 3D-TOF MR angiography without and with contrast enhancement and CT angiogr aphy. METHODS: Two nitinol stents, two nitinol-polytetrafluoroethylene (PTFE) ste nt-grafts, and two stainless steel stents were deployed in three dogs with experimental carotid aneurysms, In a fourth animal, one of three aneurysms was completely occluded with GDCs, The other two aneurysms were loosely pac ked to ensure persistence of some residual aneurysmal lumen. Cut-film angio graphy, CT angiography, 3D-TOF MR angiography without and with contrast enh ancement, and 3D MR DSA were performed in all dogs before and 3 weeks after treatment. RESULTS: SD MR DSA was superior to conventional SD-TOF MR angiography witho ut and with contrast enhancement in accurately depicting experimental later al aneurysms and superior to CT angiography in depicting aneurysms treated by GDCs, SD MR DSA and CT angiography were comparable in depicting vessels treated with nitinol stents and stent-grafts, whereas CT angiography was su perior for showing vessels treated by stainless steel stents. CONCLUSION: We recommend further development and clinical evaluation of 3D MR DSA For imaging cerebral aneurysms before and after treatment with GDCs, 3D MR DSA or CT angiography may be useful for evaluating vessels containin g nitinol stents or nitinol-PTFE stent-grafts, whereas CT angiography shoul d be used for follow-up of vessels treated by stainless steel stents.