前瞻性心电门控联合全模型迭代重建算法在左心房及肺静脉CT成像中的可行性和价值研究  

A study on feasibility and value of prospective ECG-gating with full IMR algorithm in CT imaging of left atrium and pulmonary vein

作　　者：刘建强 葛建新 刘晶哲 LIU Jian-qiang;GE Jian-xin;LIU Jing-zhe(Department of Radioautography,The First Hospital of Tsinghua University,Beijing 100016,China)

机构地区：[1]清华大学第一附属医院放射影像科

出　　处：《中国医学装备》2019年第9期20-23,共4页China Medical Equipment

基　　金：首都卫生发展科研专项(首发2014-4-4122)“CT、MRI、右心导管造影与肺血管病理分级在肺动脉高压病人及动物实验的相关性研究”

摘　　要：目的:探讨前瞻性心电门控联合全模型迭代重建(IMR)算法在左心房及肺静脉成像的可行性。方法:对42例成年房颤患者进行左心房及肺静脉iCT型256层CT成像。将患者随机分为对照组和观察组,每组21例。对照组采用回顾性门控扫描模式,滤波反投影(FBP)重建;观察组为前瞻性前置门控扫描模式,分别使用FBP和IMR进行图像重建,得到A和B两组图像。测量并计算对照组图像及观察组A、B两组图像(共3组图像)的左心房CT值、图像噪声、信噪比(SNR)和对比噪声比(CNR),并对图像质量按照5分法进行评价。比较3组图像间左心房CT值、图像噪声、SNR和CNR;分析比较两组检查的剂量长度乘积(DLP)。结果:3组图像质量主观评分均为3~5分。对照组与观察组的A和B组图像评分以及A与B组图像间评分比较,其差异均无统计学意义(t=4.092,t=5.789,t=0.146;P>0.05)。观察组中B组图像客观指标SNR和CNR均优于对照组图像和A组图像,差异均有统计学意义(t=-4.051,t=-4.751,t=-6.623,t=-6.890;P<0.05)。观察组的DLP(252.49±17.34)/mGy cm比对照组的(366.10±32.4)/mGy cm减少了33%。结论:使用前瞻性心电门控联合IMR算法进行左心房及肺静脉CT成像可以减少辐射剂量,同时提高了CT图像的SNR和CNR。Objective:To investigate the feasibility of prospective electrocardiograph(ECG)-gating combined with iterative model reconstruction(IMR)algorithm in CT imaging of left atrium and pulmonary vein.Methods:Fortytwo adult patients with atrial fibrillation(AF)underwent CT imaging by 256-slice CT scanner(iCT)on left atrium and pulmonary vein.All patients were randomly divided into control group and study group,with 21 cases in each group.Control group adopted retrospective ECG-gating scan and filtered back-projection(FBP)to implement reconstruction.Observation group adopted prospective ECG-gating scan model,and FBP and IMR were used to reconstruct image,and then image group A and image group B were obtained,respectively.CT values,image noise,signal noise ratio(SNR)and contrast to noise ratio(CNR)of left atrium of control group,observation group A and observation group B(3 groups)were measured and calculated,and the image qualities of them were evaluated according to the 5-point method.The CT value,image noise,SNR and CNR of the left atrium between the three groups were compared,and the dose-long product(DLP)between the two groups were analyzed and compared.Results:The subjective score ranges of image quality of three groups were 3-5.The differences of image score between control group and observation group A,between control group and observation group B,and between observation group A and observation group B,were no significant(t=4.092,t=5.789,t=0.146,P>0.05),respectively.The objective indicators,SNR and CNR,of observation group B were significantly higher than those of control group and observation group B(t=-4.051,t=-4.751,t=-6.623,t=-6.890,P<0.05),respectively.The DLP of observation group[(252.49±17.34)mGy·cm]was reduced to 33%of that of contrast group[(366.10±32.4)mGy·cm].Conclusion:The combination of prospective ECG-gating with full IMR algorithm can reduce the radiation dose and improve the SNR and CNR of CT image.

关 键 词：心房颤动 体层摄影术 前瞻性心电门控 辐射剂量 模型迭代重建(IMR) 

分 类 号：R197.39[医药卫生—卫生事业管理]