双源CT自适应心脏步进扫描技术在高心率患者冠状动脉成像中的应用

Application of dual-source CT coronary angiography in step-and-shoot mode in patients with high heart rate

目的探讨双源CT自适应心脏步进扫描技术在高心率患者冠状动脉成像中的应用价值。方法连续采集58例接受DSCTA检查(心率≥70次/分,均未进行人为干预)的患者资料。数据采集期相为45%R-R间期,重建期相为45%±8%。采用Kruskal Wallis H检验分析平均心率、心率变化与图像质量间的关系;ROC曲线分析检验平均心率、心率变化对移动伪影产生的影响。14例患者在DSCTA后接受冠状动脉造影(CAG)检查。采用CTDI和DLP计算有效辐射剂量。结果 58例纳入患者中,可供评价的血管为948段,图像质量评价为1～3级者占95.68%(907/948)。对于不同的心率变化,不同级别的LAD、LCX的显示节段数比较差异有统计学意义(P<0.05)。ROC曲线分析表明平均心率对冠状动脉移动伪影的产生有统计学意义(AUC:0.75,95%CI:0.55～0.96,P<0.05)。DSCTA诊断狭窄程度<50%及≥50%血管的敏感度分别为80.00%(8/10)和90.48%(38/42);诊断血管狭窄的特异度为95.51%(170/178),阴性预测值为96.59%(170/176)。有效辐射剂量为(6.46±0.12)mSv。结论双源CT自适应心脏步进扫描技术对于心率≥70次/分的患者无需刻意降低心率,心率变化平稳患者均能得到良好的图像质量,诊断效能较高,可明显降低辐射剂量。

Objective To investigate the value of dual-source CT coronary angiography （DSCTA） in step-and-shoot （SAS） mode in patients with high heart rate. Methods Fifty-eight consecutive patients （heart rates≥70 bpm） underwent DSCTA in adaptive cardio sequence without additional heart rate control were enrolled. Data sets were acquired in 45% and reconstructed in 45%±8% R-R intervals of cardiac cycle. Kruskal Wallis H test was performed. Receiver operating characteristic curve （ROC） were applied to analyze the effect of mean heart rate and heart rate changes on motion artifacts. Fourteen patients underwent coronary angiography after accepting DSCTA. The effective radiation dose was calculated. Results Diagnostic image quality rank 1—3 was obtained in 95.68% （907/948） of all coronary segments of 58 patients. There was differernce of image quality for LAD,LCX in different heart rate changes （P〈0.05）. Mean heart rate had significant effect on motion artifacts （AUC：0.75; 95%CI：0.55—0.96; P〈0.05）. The sensitivity of DSCTA in SAS mode for the 〈50% stenosis and ≥50% stenosis was 80.00% （8/10） and 90.48% （38/42）,respectively. The specificity was 95.51% （170/178） and the negative predictive value was 96.59% （170/176） in the diagnosis of coronary artery stenosis. The mean estimated effective dose was （6.46±0.12） mSv. Conclusion It is not necessary to decrease the patient＇s heart rate over 70 bpm. If the heart rates vary stably,good diagnostic image quality and high performance can be obtained with adaptive cardio sequence,meanwhile effective radiation dose can be reduced significantly.