宽体探测器CT降低金属植入物所致颌面部伪影  

Wide-detector CT for reducing maxillofacial artifacts of metal implants

作　　者：魏一娟[1] 王小鹏[1] 侯平[1] 查开继[1] 高剑波[1] WEI Yijuan;WANG Xiaopeng;HOU Ping;ZHA Kaiji;GAO Jianbo(Department of Radiology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China)

机构地区：[1]郑州大学第一附属医院放射科,河南郑州450052

出　　处：《中国介入影像与治疗学》2021年第3期165-169,共5页Chinese Journal of Interventional Imaging and Therapy

摘　　要：目的探讨宽体探测器CT虚拟单能谱影像(VMI)联合多物质伪影降低(MARS)技术降低金属植入物致颌面部伪影的效果。方法回顾性分析40例植入金属义齿后接受颌面部CT检查患者,分别重建120 kV-like、VMI(50、70、90、110、130 keV)及VMI(50、70、90、110、130 keV)+MMAR图像,测量口底及头长肌内CT值和噪声(SD),计算对比噪声比(CNR)和伪影指数(AI);对比图像间客观及主观质量评价指标。结果120 kV-like图像的SD、CNR、AI均低于50 keV VMI(P均<0.05),SD、AI均高于90、110、130 keV-VMI(P均<0.001),CNR值均低于110、130 keV-VMI(P均<0.05)。各单能量水平VMI+MMAR图像的SD、AI均低于120 kV-like图像(P均<0.001),50、70、90 keV-VMI+MMAR图像SD、AI均低于相应VMI(P均<0.05),110、130 keV-VMI+MMAR图像SD、AI与对应VMI间差异均无统计学意义(P均>0.05),各单能量水平VMI+MMAR图像CNR均高于对应VMI及120 kV-like图像(P均<0.05)。120 kV-like图像主观评分低于各单能量水平VMI+MMAR图像(P均<0.05)而高于50 keV-VMI图像(P=0.002),与70 keV及以上能量水平VMI图像评分差异均无统计学意义(P均>0.05)。各单能量水平VMI+MMAR图像主观评分均高于对应VMI(P均<0.001)。50、70、90、110 keV VMI、VMI+MMAR图像主观评分均随keV增高而增高,110 keV时评分最高,130 keV时减低(P均<0.05)。结论宽体探测器CT的VMI联合MMAR技术能有效降低金属植入物所致颌面部伪影。Objective To explore the effects of wide-detector CT virtual monoenergetic images(VMI)combined with multi-material artifact reduction(MMAR)techniques for reducing artifacts of metal implants in maxillofacial imaging.Methods Data of 40 patients with metal denture implants who underwent maxillofacial CT examinations by wide-detector CT were retrospectively analyzed.The data were then reconstructed into 120 kV-like,VMI(50,70,90,110,130 keV),VMI(50,70,90,110,130 keV)+MMAR images.CT value and standard deviations(SD)of the mouth floor and the longus scapitis at the same level were measured.The contrast to noise ratio(CNR)and artifact index(AI)were calculated.The imaging quality evaluation indexes were compared among images objectively and subjectively.Results SD,CNR and AI of 120 kV-like image were lower than those of 50 keV-VMI(all P<0.05),SD and AI were higher than those of 90,110 and 130 keV-VMI(all P<0.001),and CNR was lower than that of 110 and 130 keV-VMI(both P<0.05).SD and AI of each single energy level VMI+MMAR images were all lower than those of 120 kV-like image(all P<0.001),and those of 50,70,90 keV-VMI+MMAR images were all lower than of the corresponding VMI(all P<0.05),while no statistical difference of SD nor AI was found among 110,130 keV-VMI+MMAR images and corresponding VMI(all P>0.05),CNR of each single energy level VMI+MMAR were higher than those of the corresponding VMI and 120 kV-like images(all P<0.05).The scores of 120 kV-like images were all lower than that of VMI+MMAR images of each single energy levels(all P<0.05)but higher than that of 50 keV-VMI images(P=0.002),while there was no significant difference of those of VMI images at 70 keV and above energy levels(all P>0.05).VMI+MMAR image scores of each single energy level were higher than that of the corresponding VMI(all P<0.001).Image scores of 50,70,90,110 keV VMI and VMI+MMAR increased with the increasing of keV,the highest score was found at 110 keV but decreased at 130 keV(all P<0.05).Conclusion VMI combined with MMAR techniques of wide-

关 键 词：诊断显像 义齿 颌面假体植入 金属 体层摄影术 X线计算机 图像质量 

分 类 号：R445[医药卫生—影像医学与核医学] R814.42[医药卫生—诊断学]