Akkaya Selcuk, Akca Onur, Arat Anıl, Peker Ahmet, Balci Sinan
1 Department of Radiology, Kaçkar State Hospital, Rize, Turkey.
2 Department of Radiology, Güven Hospital, Ankara, Turkey.
Interv Neuroradiol. 2018 Dec;24(6):655-661. doi: 10.1177/1591019918785910. Epub 2018 Jul 5.
Low-profile, self-expandable stents are used to treat wide-neck aneurysms located on the smaller distal intracranial arteries. This study aimed to assess the usefulness of time-of-flight (TOF) and contrast-enhanced (CE) magnetic resonance angiography (MRA) for follow-up after LEO Baby stent (LBS)-assisted coil embolization.
Twenty-four aneurysms treated with LBS-assisted coil embolization were evaluated. Researchers reviewed TOF MRA and CE MRA images in terms of occlusion and stent patency. Aneurysm occlusion was graded according to Raymond-Roy classification as follows: total occlusion (grade 1), residual neck (grade 2), and residual aneurysm (grade 3). Stent patency was scored as follows: occlusion (1), stenosis (2), and normal (3). Interobserver and intermodality agreement values were determined by weighted kappa (κ) statistics.
Intermodality and interobserver values of TOF MRA and CE MRA with digital subtraction angiography (DSA) were perfect (κ = 1.00, p < 0.001) in terms of aneurysm occlusion. Rate of stent occlusion and stenosis in DSA, TOF, and MRA, respectively, were as follows: 0 and 12.5%, 16.6 and 70.8%, and 0 and 62.5%. Intermodality agreement values of TOF MRA and CE MRA with DSA were insignificant in terms of stent patency (κ = 0.065, p = 0.27; κ = 0.158, p = 0.15, respectively). Interobserver agreement was substantial in both TOF MRA (κ = 0.71, p < 0.001) and CE MRA (κ = 0.64, p = 0.001).
Both TOF and CE MRA techniques have strong concordance with DSA for the detection of aneurysm occlusion status. CE MRA can be used as a first-line noninvasive imaging modality due to its superiority to TOF MRA with respect to the visualization of in-stent signals.
低轮廓、自膨式支架用于治疗位于颅内较小远端动脉的宽颈动脉瘤。本研究旨在评估时间飞跃（TOF）和对比增强（CE）磁共振血管造影（MRA）在LEO Baby支架（LBS）辅助弹簧圈栓塞术后随访中的应用价值。
对24例接受LBS辅助弹簧圈栓塞治疗的动脉瘤进行评估。研究人员根据闭塞情况和支架通畅性对TOF MRA和CE MRA图像进行了回顾。动脉瘤闭塞情况根据Raymond-Roy分类进行分级，如下：完全闭塞（1级）、残留颈部（2级）和残留动脉瘤（3级）。支架通畅性评分如下：闭塞（1分）、狭窄（2分）和正常（3分）。观察者间和模态间一致性值通过加权kappa（κ）统计量确定。
在动脉瘤闭塞方面，TOF MRA和CE MRA与数字减影血管造影（DSA）的模态间和观察者间一致性值均为完美（κ = 1.00，p < 0.001）。DSA、TOF和MRA中支架闭塞和狭窄的发生率分别如下：0%和12.5%、16.6%和70.8%、0%和62.5%。在支架通畅性方面，TOF MRA和CE MRA与DSA的模态间一致性值无统计学意义（κ = 0.065，p = 0.27；κ = 0.158，p = 0.15）。观察者间一致性在TOF MRA（κ = 0.71，p < 0.001）和CE MRA（κ = 0.64，p = 0.001）中均为显著。
TOF和CE MRA技术在检测动脉瘤闭塞状态方面与DSA具有高度一致性。由于CE MRA在支架内信号可视化方面优于TOF MRA，因此可作为一线无创成像方式。
