单能量去金属伪影算法在心脏起搏器中去伪影效果评价

Evaluation of Single-Energy Metal Artifact Reduction Algorithm in Cardiac Pacemaker Implantation

目的:研究单能量去金属伪影(SEMAR)算法在心脏起搏器植入术后的去伪影效果,探讨其对无导线起搏器与有导线起搏器改善图像质量的效果对比。方法:前瞻性收集心脏起搏器植入术后行冠状动脉CT血管成像(CCTA)患者的图像,进行两次容积重建:一次使用自适应迭代算法重建(非SEMAR组);一次使用自适应迭代算法联合SEMAR算法重建(SEMAR组)。在金属伪影覆盖面积最大的层面,高、低密度伪影区的右冠状动脉及周围脂肪组织等划取感兴趣区(ROI),记录CT值和标准差以计算伪影指数(AI)对图像进行客观评价,由2名高年资放射科医师采取双盲法对图像质量行主观评价,并采用Kappa检验评估观察者间的一致性。结果:共计32例心脏起搏器植入术后患者被纳入评价。2名阅片者主观评分一致性良好(κ=0.92)。SEMAR组比非SEMAR组主观评分高(P<0.01)。SEMAR组无导线起搏器主观评分高于有导线起搏器(P<0.01)。起搏器(总体),有、无导线起搏器组内比较,SEMAR组AI值均低于非SEMAR组(P<0.01)。有、无导线起搏器组间比较,SEMAR前后AI值相同(P>0.05)。结论:SEMAR算法能够有效减少心脏起搏器金属伪影,改善图像质量,其在无导线起搏器中改善图像质量的效果优于有导线起搏器。

Purpose:To evaluate the efficacy of single-energy metal artifact reduction(SEMAR)algorithm in reducing metal artifacts from cardiac pacemakers,and to compare its impact on improving image quality between leadless and transvenous pacemakers.Methods:Patients who underwent coronary CT angiography(CCTA)after pacemaker implantation were prospectively collected.The data were reconstructed using two methods:one using adaptive iterative dose reduction three-dimensional algorithm(non-SEMAR group),and the other performing with the addition of a SEMAR algorithm(SEMAR group).At the level contained the largest coverage of metal artifact,regions of interest(ROIs)were placed in the tissue affected by hypo-and hyperdense artifacts,including the right coronary artery and pericoronary adipose tissue.The CT value and standard deviation within each ROI were recorded to calculate artifact index(AI).The subjective image quality was evaluated by two senior radiologists with doubleblind method.Cohen's Kappa test was also used to assess the inter-observer agreement.Results:A total of 32 patients after pacemaker implantation were included in this study.There was a good consistency in the subjective scores of the two radiologists(κ=0.92).The SEMAR group exhibited higher subjective scores compared to the non-SEMAR group(P<0.01).The subjective score of leadless pacemaker in SEMAR group significantly surpassed that of transvenous pacemakers(P<0.01).Overall,in both leadless and transvenous pacemakers,the SEMAR group exhibited lower AI values than that of the non-SEMAR group(P<0.01).Before or after using SEMAR algorithm,the AI values of leadless pacemaker were comparable to those of transvenous pacemakers(P>0.05).Conclusions:SEMAR algorithm can effectively reduce metal artifacts from cardiac pacemakers.In addition,it has better image quality improvement in leadless pacemaker compared to transvenous pacemakers.