Department Radiology, Academic Medical Center, Amsterdam, the Netherlands.
AJNR Am J Neuroradiol. 2009 Oct;30(9):1665-71. doi: 10.3174/ajnr.A1678. Epub 2009 Jul 23.
MR angiography (MRA) is increasingly used as a noninvasive imaging technique for the follow-up of coiled intracranial aneurysms. However, the need for contrast enhancement has not yet been elucidated. We compared 3D time-of-flight MRA (TOF-MRA) and contrast-enhanced MRA (CE-MRA) at 3T with catheter angiography.
Sixty-seven patients with 72 aneurysms underwent TOF-MRA, CE-MRA, and catheter-angiography 6 months after coiling. Occlusion status on MRA was classified as adequate (complete and neck remnant) or incomplete by 2 independent observers. For TOF-MRA and CE-MRA, interobserver agreement, intermodality agreement, and correlation with angiography were assessed by kappa statistics.
Catheter-angiography revealed incomplete occlusion in 12 (17%) of the 69 aneurysms; 3 aneurysms were excluded due to MR imaging artifacts. Interobserver agreement was good for CE-MRA (kappa = 0.77; 95% confidence interval [CI], 0.55-0.98) and very good for TOF-MRA (kappa = 0.89; 95% CI, 0.75-1.00). Correlation of TOF-MRA and CE-MRA with angiography was good. The sensitivity of TOF-MRA and CE-MRA was 75% (95% CI, 43%-95%); the specificity of TOF-MRA was 98% (95% CI, 91%-100%) and of CE-MRA, 97% (95% CI, 88%-100%). All 5 incompletely occluded aneurysms, which were additionally treated, were correctly identified with both MRA techniques. Areas under the receiver operating characteristic curve for TOF-MRA and CE-MRA were 0.90 (95% CI, 0.79-1.00) and 0.91 (95% CI, 0.79-1.00). Intermodality agreement between TOF-MRA and CE-MRA was very good (kappa = 0.83; 95% CI, 0.65-1.00), with full agreement in 66 (96%) of the 69 aneurysms.
In this study, TOF-MRA and CE-MRA at 3T were equivalent in evaluating the occlusion status of intracranial aneurysms after coiling. Because TOF-MRA does not involve contrast administration, this method is preferred over CE-MRA.
磁共振血管造影（MRA）作为一种非侵入性成像技术，在颅内已被广泛应用于线圈栓塞后动脉瘤的随访。然而，目前仍不清楚是否需要增强对比。我们比较了 3T 下的三维时间飞跃 MRA（TOF-MRA）和对比增强 MRA（CE-MRA）与导管血管造影的结果。
67 例 72 个动脉瘤患者在 coil 栓塞后 6 个月进行了 TOF-MRA、CE-MRA 和导管血管造影。2 名独立观察者根据闭塞情况将 MRA 分为完全闭塞（完全闭塞伴颈部残端）和不完全闭塞。对 TOF-MRA 和 CE-MRA，采用 Kappa 统计分析评估观察者间一致性、两种模态间一致性以及与血管造影的相关性。
导管血管造影显示 69 个动脉瘤中有 12 个（17%）存在不完全闭塞；由于磁共振成像伪影，3 个动脉瘤被排除。CE-MRA 的观察者间一致性良好（Kappa = 0.77；95%置信区间 [CI]，0.55-0.98），TOF-MRA 的观察者间一致性非常好（Kappa = 0.89；95% CI，0.75-1.00）。TOF-MRA 和 CE-MRA 与血管造影的相关性良好。TOF-MRA 和 CE-MRA 的灵敏度分别为 75%（95% CI，43%-95%）和 75%（95% CI，43%-95%）；TOF-MRA 的特异性为 98%（95% CI，91%-100%），CE-MRA 的特异性为 97%（95% CI，88%-100%）。所有 5 个未完全闭塞的动脉瘤（均接受了额外治疗）均通过两种 MRA 技术正确识别。TOF-MRA 和 CE-MRA 的受试者工作特征曲线下面积分别为 0.90（95% CI，0.79-1.00）和 0.91（95% CI，0.79-1.00）。TOF-MRA 和 CE-MRA 之间的模态间一致性非常好（Kappa = 0.83；95% CI，0.65-1.00），69 个动脉瘤中有 66 个（96%）完全一致。
在本研究中，3T 下的 TOF-MRA 和 CE-MRA 在评价颅内动脉瘤 coil 栓塞后的闭塞情况方面具有等效性。由于 TOF-MRA 不涉及对比剂的应用，因此该方法优于 CE-MRA。
