Serial cerebral angiographic imaging is necessary to ensure cerebral aneurysm occlusion after flow diverter placement. Time-of-flight (TOF)-magnetic resonance angiography (MRA) is used for this purpose due to its lack of radiation, contrast media and complications. The comparative diagnostic yield of TOF-MRA for different flow diverters has not been previously analyzed. To evaluate the diagnostic accuracy of TOF-MRA in cerebral aneurysms treated w divertersith different flow diverters. Flow-diverted patients whose cerebral follow-up MRA and digital subtraction angiograms (DSA) were obtained within 6 weeks were retrospectively identified. The DSA (as gold standard) and MRA images of these patients were compared by two readers (blinded to both patient data and endovascular procedure data) for residual aneurysms and the status of the parent artery for each type of flow diverter. In a second group of patients, magnetic susceptibility artifacts were manually measured and compared for different FDs. Seventy-six patients (85 aneurysms) were included in group one, and 86 patients (95 aneurysms) were included in group 2. TOF-MRA and DSA showed almost perfect agreement for residual aneurysms (κ = 0.88, p < 0.001) (positive predictive value (PPV) = 1.00, specificity = 1.00, negative predictive value (NPV) = 0.89, sensitivity = 0.89). Intermodality agreement (κ = 0.97 vs. κ = 0.74, p < 0.005) and sensitivity (0.97 vs. 0.77, NPV: 0.96 vs. 0.77) were highest with nitinol stents. MRA and DSA showed no agreement for occluded or stenotic parent vessels (κ = 0.13, p = 0.015, specificity = 0.44, NPV = 1.00, sensitivity = 1.00). Specificity was lower in chromium-cobalt based FDs than in nitinol devices (specificity = 0.08 vs. 0.60). Chromium-cobalt stents generated the largest artifacts (p < 0.005). The size of the device-related artifact, in millimeters, increased in respective order, for the Silk, Derivo, Pipeline and Surpass devices. Unlike DSA, TOF-MRA is susceptible to dissimilarities between flow diverters. MRA is not well-suited for research studies comparing different flow diverters. Nitinol FDs appear to be advantageous for TOF-MRA follow-up so as not to miss small aneurysm remnants or clinically relevant parent artery stenosis.

中文翻译：

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不同类型颅内分流器引起的磁共振血管造影伪影的影响


连续脑血管造影成像对于确保放置分流器后脑动脉瘤闭塞是必要的。飞行时间 (TOF) 磁共振血管造影 (MRA) 由于缺乏辐射、造影剂和并发症而被用于此目的。之前尚未分析过不同分流器的 TOF-MRA 诊断率的比较。评价 TOF-MRA 对采用不同分流器治疗的脑动脉瘤的诊断准确性。回顾性鉴定6周内获得脑MRA随访和数字减影血管造影（DSA）的血流改道患者。由两名读者（对患者数据和血管内手术数据不知情）比较这些患者的 DSA（作为金标准）和 MRA 图像，以了解每种类型分流器的残余动脉瘤和载瘤动脉的状态。在第二组患者中，手动测量磁化率伪影并比较不同 FD 的情况。第一组包括 76 名患者（85 个动脉瘤），第二组包括 86 名患者（95 个动脉瘤）。TOF-MRA 和 DSA 显示残余动脉瘤几乎完全一致 (κ = 0.88，p < 0.001)（阳性预测值 (PPV) = 1.00，特异性 = 1.00，阴性预测值 (NPV) = 0.89，敏感性 = 0.89）。镍钛诺支架的多模态一致性（κ = 0.97 vs. κ = 0.74，p < 0.005）和敏感性（0.97 vs. 0.77，NPV：0.96 vs. 0.77）最高。 MRA 和 DSA 未显示闭塞或狭窄载瘤血管的一致性（κ = 0.13，p = 0.015，特异性 = 0.44，NPV = 1.00，敏感性 = 1.00）。铬钴基 FD 的特异性低于镍钛诺装置（特异性 = 0.08 vs. 0.60）。 铬钴支架产生的伪影最大 (p < 0.005)。对于 Silk、Derivo、Pipeline 和 Surpass 设备，设备相关工件的尺寸（以毫米为单位）按各自的顺序增加。与 DSA 不同，TOF-MRA 容易受到分流器之间差异的影响。 MRA 不太适合比较不同分流器的研究。镍钛诺 FD 似乎有利于 TOF-MRA 随访，以免错过小动脉瘤残留或临床相关的载瘤动脉狭窄。