125I粒子植入术后腹部CT金属伪影抑制的iMAR最佳预设参数研究

The optimal preset of i MAR to reduce the metal artifact of125I seeds in abdominal CT

目的:研究降低125I粒子植入术后腹部CT去金属伪影迭代算法(i MAR)的最佳预设参数。方法:纳入2023年1月—2024年4月在我院行腹部125I粒子植入手术的患者17例。其腹部CT图像使用8种目前设备提供的i MAR预设进行后处理。在每组图像中,分别把感兴趣区放置在受125I粒子伪影影响的邻近组织区、125I粒子周围最明显的低密度伪影区、高密度伪影区和对侧腰大肌区。每组图像的伪影指数(AI)、含伪影组织ROI内的标准差值(SD)及主观评分值与没有使用i MAR(i MARNO)图像的测量值进行组间统计分析。结果:在8种预设参数中,颅内金属圈(NC)预设参数组的图像的AI值、SD值最低。在主观评分中NC预设参数组图像也得到了最高的主观评分值。结论:在i MAR的8种预设参数中,NC预设参数对减少腹部125I粒子植入术后CT成像金属伪影的效果最为显著。

Objective:To investigate the optimal preset parameters of iterative metal artifact reduction(iMAR)for reducing metal artifacts in abdominal CT after~(125)I seeds implantation.Methods:Seventeen patients who underwent abdominal~(125)I seeds implantation surgery in our hospital from January 2023 to April 2024 were included.The abdominal CT images were post processed using eight currently available i MAR presets.In each set of images,the region of interest is placed in the adjacent tissue area affected by the~(125)I seeds,the low-density artifact area around the~(125)I seeds,the high-density artifact area,and the contralateral vertebral muscle.The artifact index(AI),standard deviation(SD)within the ROI and subjective scoring values of each group of images were compared with images without i MAR(iMARNO).Results:Among the eight presets,the AI and SD values of the images in the neuro-coils(NC)preset parameter group were the lowest.In subjective evaluation,the NC preset group image also obtained the highest subjective evaluation value.Conclusion:Among the eight presets for i MAR,the NC preset has the most significant effect on reducing CT imaging artifacts after abdominal~(125)I seeds implantation.