Agid R, Schaaf M, Farb Ri
Department of Medical Imaging, Toronto Western Hospital, Toronto, Ontario, Canada.
Interv Neuroradiol. 2012 Sep;18(3):275-83. doi: 10.1177/159101991201800305. Epub 2012 Sep 10.
This study compared the accuracy of contrast-enhanced MR angiography (CE-MRA) to intra-arterial cerebral angiography (IA-DSA) for assessment of intracranial aneurysms after stent-assisted coiling and to check if the presence of a stent in the parent artery diminishes the accuracy of CE-MRA. Consecutive patients with cerebral aneurysms treated by stent-assisted coiling were evaluated retrospectively. Matching follow-up CE-MRA and IA-DSA were evaluated separately. Evaluation included the presence of aneurysmal remnant, patency and stenosis of parent artery. Twenty-seven patients with 28 aneurysms and 33 matched CE-MRA and IA-DSA studies were evaluated. Nineteen aneurysmal remnants were seen on CE-MRA and 16 on IA-DSA. CE-MRA diagnosed three aneurysmal remnants not appreciated on IA-DSA. Five other remnants were larger on CE-MRA than IA-DSA. None of the remnants were missed on CE-MRA. Parent arteries were patent on both modalities. CE-MRA showed false stenosis of the stented artery in six cases and exaggerated stenosis in two. In 18 cases, CE-MRA showed a short focal "pseudo-stenosis" where the stent's marker bands were located. This was noted whenever the stent's marker bands were located in an artery with luminal diameter ≤2 mm and was called "marker band effect". CE-MRA is an accurate technique for follow-up of aneurysms post stent-assisted coiling with excellent depiction of remnants in spite of the presence of a stent. Apparent stenosis of the stented parent artery on CE-MRA is often false or exaggerated. "Marker band effect" should be recognized as an artifact that appears when stent's marker bands are in a small artery.
本研究比较了对比增强磁共振血管造影（CE-MRA）与动脉内脑血管造影（IA-DSA）在评估支架辅助弹簧圈栓塞术后颅内动脉瘤方面的准确性，并检查载瘤动脉中支架的存在是否会降低CE-MRA的准确性。对接受支架辅助弹簧圈栓塞治疗的连续性脑动脉瘤患者进行回顾性评估。分别对匹配的随访CE-MRA和IA-DSA进行评估。评估内容包括动脉瘤残余的存在、载瘤动脉的通畅性和狭窄情况。对27例患有28个动脉瘤的患者以及33组匹配的CE-MRA和IA-DSA研究进行了评估。在CE-MRA上发现19个动脉瘤残余，在IA-DSA上发现16个。CE-MRA诊断出3个IA-DSA未发现的动脉瘤残余。另外5个残余在CE-MRA上比在IA-DSA上更大。CE-MRA没有漏诊任何残余。两种检查方式下载瘤动脉均通畅。CE-MRA显示6例支架置入动脉存在假狭窄，2例存在夸大狭窄。在18例中，CE-MRA在支架标记带所在位置显示出短段局灶性“假性狭窄”。当支架标记带位于管腔直径≤2mm的动脉中时会出现这种情况，被称为“标记带效应”。CE-MRA是一种准确的技术，用于支架辅助弹簧圈栓塞术后动脉瘤的随访，尽管存在支架，但仍能很好地显示残余情况。CE-MRA上显示的支架置入载瘤动脉的明显狭窄通常是假的或夸大的。“标记带效应”应被视为当支架标记带位于小动脉中时出现的一种伪影。
