Mochizuki Junji, Oyama-Manabe Noriko, Kato Fumi, Takahashi Hideki, Manabe Osamu, Sawada Akihiro, Okamura Homare, Nakano Mitsunori, Yamaguchi Atsushi
Department of Radiology, Jichi Medical University Saitama Medical Center, 1-847 Amanuma-Cho, Omiya- Ku, Saitama, 330-8503, Japan.
Department of Radiology, Minamino Cardiovascular Hospital, 1-25-1, Hyoue, Hachioji, Tokyo, 192-0918, Japan.
Int J Cardiovasc Imaging. 2025 Feb;41(2):369-376. doi: 10.1007/s10554-024-03318-1. Epub 2025 Jan 18.
This study aimed to evaluate the efficacy of the single-energy metal artifact reduction (SEMAR) algorithm in reducing metal artifacts and enhancing image quality in contrast-enhanced computed tomography (CT) for patients undergoing endovascular aneurysm repair (EVAR) with coil embolization. Thirty-eight patients (mean age 81.0 ± 6 years; 31 men, 7 women) who underwent contrast-enhanced CT following EVAR and internal iliac artery coil embolization between September 2022 and May 2023 were retrospectively analyzed. The Artifact Index (AI) quantified metallic artifacts from internal iliac artery aneurysm coils in CT images, calculated from the standard deviation of the artifact-containing region relative to a reference region. CT values of the external iliac artery at the same slice were also evaluated and compared. Two radiologists independently performed qualitative assessments of SEMAR and non-SEMAR images. SEMAR significantly reduced metal artifacts, decreasing the AI from 171.9 ± 74.5 HU to 35.8 ± 16.9 HU (p < 0.001). The mean CT values of the external iliac artery were similar for SEMAR (259.4 ± 63.7 HU) and non-SEMAR (257.1 ± 63.6 HU, indicating no significant difference. Qualitative assessment scores improved significantly with SEMAR (from 1.0 ± 0.0 to 2.5 ± 0.5; p < 0.001), enhancing visualization of internal iliac artery aneurysms. Interobserver agreement was high (κ = 0.83). The SEMAR algorithm effectively reduces metal artifacts in contrast-enhanced CT, significantly enhancing image quality without altering adjacent artery CT values. These improvements enhance the image quality of post-operative assessments in patients undergoing EVAR with coil embolization.
本研究旨在评估单能量金属伪影减少（SEMAR）算法在减少血管内动脉瘤修复（EVAR）并采用弹簧圈栓塞治疗的患者的对比增强计算机断层扫描（CT）中金属伪影及提高图像质量方面的疗效。对2022年9月至2023年5月期间接受EVAR及髂内动脉弹簧圈栓塞后进行对比增强CT检查的38例患者（平均年龄81.0±6岁；男性31例，女性7例）进行回顾性分析。伪影指数（AI）用于量化CT图像中来自髂内动脉动脉瘤弹簧圈的金属伪影，通过含伪影区域相对于参考区域的标准差计算得出。同时评估并比较同一层面髂外动脉的CT值。两名放射科医生独立对采用SEMAR和未采用SEMAR的图像进行定性评估。SEMAR显著减少了金属伪影，AI从171.9±74.5 HU降至35.8±16.9 HU（p<0.001）。SEMAR组（259.4±63.7 HU）和未采用SEMAR组（257.1±63.6 HU）髂外动脉的平均CT值相似，表明无显著差异。采用SEMAR后定性评估分数显著提高（从1.0±0.0提高至2.5±0.5；p<0.001），增强了髂内动脉瘤的可视化。观察者间一致性较高（κ=0.83）。SEMAR算法有效减少了对比增强CT中的金属伪影，显著提高了图像质量，且未改变相邻动脉的CT值。这些改善提高了接受EVAR并采用弹簧圈栓塞治疗患者术后评估的图像质量。
