Insufficient slow-flow suppression mimicking aneurysm wall enhancement in magnetic resonance vessel wall imaging: a phantom study
Insufficient slow-flow suppression mimicking aneurysm wall enhancement in magnetic resonance vessel wall imaging: a phantom study
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DOI：
10.3171/2019.4.focus19235
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发表时间：
2019-07-01
影响因子：
4.1
通讯作者：
Majoie, Charles B. L. M.
中科院分区：
文献类型：
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作者：
Cornelissen, Bart M. W.;Leemans, Eva L.;Majoie, Charles B. L. M.
目的磁共振血管壁成像(VWI)越来越多地应用于临床，以支持颅内动脉瘤的治疗决策。预计注射造影剂后的动脉瘤壁强化与动脉瘤的不稳定和破裂状态有关。然而，作者假设慢流伪影与动脉瘤壁强化相似。因此，在这项体模研究中，他们使用不同的MR VWI技术来评估慢血流对壁样强化的影响。方法作者开发了一种与MR兼容的动脉瘤体模模型，该模型连接到一个泵，以实现脉动流入条件。对于VWI，使用3-T磁共振扫描仪进行3D快速自旋回波序列(包括有和没有运动敏化驱动平衡(MSDE)和定制激励(Dante)准备脉冲的延迟与章动交替)。分别在注射Gd造影剂前后采用两种不同的脉动血流条件(峰值流速为2.5ml/s，峰值频率分别为77次/min和48次/min)。结果在注射造影剂后，特别是在低泵率的情况下，作者观察到了壁样强化。制备脉冲，特别是Dante技术，改善了慢流抑制的性能。结论近壁慢流模拟了VWI方案中的壁面增强。因此，应仔细解读VWI。制备脉冲改善了慢流抑制，因此作者鼓励进一步开发和临床应用这些技术。
OBJECTIVE MR vessel wall imaging (VWI) is increasingly performed in clinical settings to support treatment decision-making regarding intracranial aneurysms. Aneurysm wall enhancement after contrast agent injection is expected to be related to aneurysm instability and rupture status. However, the authors hypothesize that slow-flow artifacts mimic aneurysm wall enhancement. Therefore, in this phantom study they assess the effect of slow flow on wall-like enhancement by using different MR VWI techniques.METHODS The authors developed an MR-compatible aneurysm phantom model, which was connected to a pump to enable pulsatile inflow conditions. For VWI, 3D turbo spin echo sequences-both with and without motion-sensitized driven equilibrium (MSDE) and delay alternating with nutation for tailored excitation (DANTE) preparation pulses-were performed using a 3-T MR scanner. VWI was acquired both before and after Gd contrast agent administration by using two different pulsatile inflow conditions (2.5 ml/sec peak flow at 77 and 48 beats per minute). The intraluminal signal intensity along the aneurysm wall was analyzed to assess the performance of slow-flow suppression.RESULTS The authors observed wall-like enhancement after contrast agent injection, especially in low pump rate settings. Preparation pulses, in particular the DANTE technique, improved the performance of slow-flow suppression.CONCLUSIONS Near-wall slow flow mimics wall enhancement in VWI protocols. Therefore, VWI should be carefully interpreted. Preparation pulses improve slow-flow suppression, and therefore the authors encourage further development and clinical implementation of these techniques.