Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany.
Department of Diagnostic and Interventional Radiology, Heidelberg University Hospital, Heidelberg, Germany.
J Neurointerv Surg. 2022 Aug;14(8):832-836. doi: 10.1136/neurintsurg-2021-018018. Epub 2021 Aug 25.
Onyx is frequently used for endovascular embolization of intracranial arteriovenous malformations (AVMs) and dural arteriovenous fistulas (dAVFs). One drawback of using Onyx is the generation of artifacts in cone-beam CT (CBCT). These artifacts can represent an obstacle for the detection of periprocedural hemorrhage or planning of subsequent radiosurgery. This study investigates the effect of artifact reduction by the syngo DynaCT SMART Metal Artifact Reduction (MAR) software.
A standardized in vitro tube model (n=10) was filled with Onyx 18 and CBCT image acquisition was conducted in a brain imaging phantom. Furthermore, post-interventional CBCT images of 20 patients with AVM (n=13) or dAVF (n=7), each treated with Onyx, were investigated. The MAR software was applied for artifact reduction. Artifacts of the original and the post-processed images were analyzed quantitatively (standard deviation in a region of interest on the layer providing the most artifacts) and qualitatively. For the patient images, the effect of the MAR software on brain parenchyma on artifact-free images was further investigated.
Quantitative and qualitative analyses of both datasets demonstrated a lower degree of artifacts in the post-processed images (eg, patient images: 38.30±22.03 density units (no MAR; mean SD±SD) vs 19.83±12.31 density units (with MAR; p<0.001). The MAR software had no influence on the brain parenchyma in artifact-free images.
The MAR software significantly reduced the artifacts evoked by Onyx in CBCT without affecting the visualization of brain parenchyma on artifact-free images. Applying this software could thus improve the quality of periprocedural CBCT images after embolization with Onyx.
Onyx 常用于颅内动静脉畸形（AVM）和硬脑膜动静脉瘘（dAVF）的血管内栓塞。使用 Onyx 的一个缺点是在锥形束 CT（CBCT）中产生伪影。这些伪影可能成为检测围手术期出血或规划后续放射手术的障碍。本研究旨在研究使用 syngo DynaCT SMART Metal Artifact Reduction（MAR）软件减少伪影的效果。
使用标准化的体外管模型（n=10）填充 Onyx 18，并在脑成像体模中进行 CBCT 图像采集。此外，对 20 例接受 Onyx 治疗的 AVM（n=13）或 dAVF（n=7）患者的介入后 CBCT 图像进行了研究。应用 MAR 软件进行伪影减少。对原始和后处理图像的伪影进行了定量（在提供最多伪影的层的感兴趣区域中的标准偏差）和定性分析。对于患者图像，进一步研究了 MAR 软件对无伪影图像中脑实质的影响。
对两个数据集的定量和定性分析表明，后处理图像中的伪影程度较低（例如，患者图像：38.30±22.03 密度单位（无 MAR；平均值±标准差±标准差）与 19.83±12.31 密度单位（有 MAR；p<0.001）。MAR 软件对无伪影图像中的脑实质没有影响。
MAR 软件可显著减少 CBCT 中由 Onyx 引起的伪影，而不影响无伪影图像中脑实质的可视化。因此，在使用 Onyx 进行栓塞后，应用该软件可以提高围手术期 CBCT 图像的质量。
