PURPOSE The aim of the present study was to assess image quality improvement using a metal artifact reduction (MAR) algorithm in cases of medium or large cerebral aneurysms treated with stent-assisted coil embolization (SAC), and to analyze factors associated with the usefulness of the MAR algorithm. METHODS We retrospectively evaluated the cone-beam computed tomography (CBCT) data sets of 18 patients with cerebral aneurysms treated with SAC. For subjective analysis, images of all cases with and without MAR processing were evaluated by five neurosurgeons based on four criteria using a five-point scale. For objective analysis, the CT values of all cases with and without MAR processing were calculated. In addition, we assessed factors associated with the usefulness of the MAR by analyzing the nine cases in which the median score for criterion 1 improved by more than two points. RESULTS MAR processing improved the median scores for all four criteria in 17/18 cases (94.4%). Mean CT values of the region of interest at the site influenced by metal artifacts were significantly reduced after MAR processing. The maximum diameter of the coil mass (< 17 mm; odds ratio [OR], 4.0; 95% confidence interval [CI], 1.2-13.9; p = 0.02) and vessel length covered by metal artifacts (< 24 mm; OR, 2.3; 95% CI, 1.1-4.7; p = 0.03) was significantly associated with the usefulness of the MAR. CONCLUSIONS This study suggests the feasibility of a MAR algorithm to improve the image quality of CBCT images in patients who have undergone SAC for medium or large aneurysms.

中文翻译：

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金属伪影减少算法，用于通过支架辅助线圈栓塞治疗的中型或大型脑动脉瘤的锥形束CT图像质量的改善。

目的本研究的目的是评估在支架辅助线圈栓塞（SAC）治疗的中型或大型脑动脉瘤情况下，使用金属伪影减少（MAR）算法评估图像质量的改善情况，并分析与以下因素相关的因素： MAR算法。方法我们回顾性评估了18例接受SAC治疗的脑动脉瘤患者的锥形束计算机断层扫描（CBCT）数据集。为了进行主观分析，由五名神经外科医生根据五项量表的四项标准对所有有或无MAR处理的病例的图像进行评估。为了进行客观分析，计算了有无MAR处理的所有病例的CT值。此外，我们通过分析9项标准1的中位数得分提高了2分以上的案例，评估了与MAR的有用性相关的因素。结果MAR处理改善了17/18例中所有四个标准的中位数（94.4％）。MAR处理后，受金属伪影影响的部位感兴趣区域的平均CT值显着降低。线圈质量的最大直径（<17毫米；比值比[OR]，4.0； 95％置信区间[CI]，1.2-13.9； p = 0.02）和被金属伪影覆盖的容器长度（<24毫米；或， 2.3; 95％CI，1.1-4.7; p = 0.03）与MAR的有效性显着相关。结论这项研究表明，MAR算法可改善中，大型动脉瘤SAC患者的CBCT图像的图像质量。