冠状动脉追踪冻结技术对高心率受检者CT冠状动脉成像质量的影响

The Effect of Snap Shot Freeze( SSF) Motion Correction Algorthm at a High Heart-Rate Range on The Image Quality of Coronary CT Angiography

目的探讨冠状动脉追踪冻结（SSF）技术对高心率（85-135 bpm）受检者CT冠状动脉成像质量的影响。方法搜集冠状动脉CT造影的228例患者,其中188例患者扫描前未服用控制心率药物;对照组控制心率患者40例,扫描前常规服用倍他乐克,减少心率变异性;回顾性心电门控和单扇区重组扫描技术,原始数据使用标准算法（STD）和SSF两种方法重组,由2名资深医师采用双盲法判读,采用4分评分法对冠状动脉血管每个阶段进行评分,≤3分为可诊断图像。对STD和SSF两种算法数据图像整体质量的比较采用卡方检验,对节段水平图像质量等级评分采用配对设计两样本比较的秩和检验（Wilcoxon两样本比较法）分析。结果 188例患者共评价冠状动脉节段1494段,可显示节段1494段,显示率100%;STD重组算法组冠状动脉可诊断节段总数为1415段,不可诊断节段共79段,总体可诊断率94.7%。SSF重组算法组冠状动脉可诊断节段为1450段,不可诊断节段共44段,总体可诊断率97.1%。两种算法冠脉总体可诊断率比较,其差异有统计学意义（χ2=812.02,P〈0.05）。40例对照组STD重组算法冠状动脉可诊断节段总数为469段,不可诊断节段共19段,总体可诊断率96.1%。SSF重组算法冠状动脉可诊断节段总数为485段,不可诊断节段共3段,总体可诊断率99.4%。两种算法冠状动脉总体可诊断率比较,其差异有统计学意义（χ2=865.84,P〈0.05）。基于节段水平分析,两种重组算法图像质量差异有统计学意义（P〈0.05）。结论与STD相比,SSF对中低心率和高心率冠状动脉节段图像质量均有改善,但对易受高心率心脏运动影响的右冠状动脉节段效果更为显著,高心率受检者CT冠脉成像采用SSF技术,可以显著减轻运动伪影,提高右冠状动脉图像质量。

Objective To evaluate the effect of Snap Shot Freeze（ SSF） motion correction algorithm at a high heart-rate（ HR） range（ 85- 135 bpm） on the image quality of coronary CT angiography（ CCTA）. Methods Retrospective electrocardiogram-gated CCTA was performed on 228 consecutive patients with HR between85 and 135 bpm using a Optima CT680 scanner. the patients were not taking any drug to control heart rate. As the matched group,40 patients taking betaloc to control heart rate. Retrospective standard reconstruction and SSF in single segment were performed for each patient. The images were interpreted in an intent-to-diagnose fashion by two experienced readers using a 4-point scale,with 3 points as diagnostically acceptable. Image quality among the two reconstruction groups were compared on paired Chi-square test and in per segmental level were compared on paired Wilcoxon rank sum test. Results A total of 1494 coronary segments were assessed for188 patients. All of the1494 segments can be shown; STD diagnosable segmental arteries reconstruction algorithm group a total of 1415 segments,not clinical segments 79,the overall diagnostic rate of 94. 7 ﹪（ 1415 /1494）. SSF diagnosable segmental arteries reconstruction algorithm group a total of 1450 segments,not diagnosis for segments 44,the overall diagnostic rate of 97. 1 ﹪（ 1450 /1494）. Algorithm of two kinds of coronary overall diagnostic rate comparison,the difference was statistically significant（ χ2= 812. 02,P 〈 0. 05）. Among the 40 patients,STD diagnosable segmental arteries reconstruction algorithm group a total of 469 segments,not clinical segments 19,the overall diagnostic rate of 96. 1 ﹪（ 469 /488）. SSF diagnosable segmental arteries reconstruction algorithm group a total of 485 segments,not diagnosis for segments 3,the overall diagnostic rate of 99. 4 ﹪（ 485 /488）. Algorithm of two kinds of coronary overall diagnostic rate comparison,the difference was statistically significant（ χ2= 865. 84,P 〈 0. 05）,Analysis at the segment level also showed statistically significant difference between the two algorithms in image quality. compared with STD,SSF to the influence of high heart rate heart movement right coronary artery segments,especially improve the image quality. reconstruction. Conclusion The SSF algorithm can eliminate or reduce coronary artery motion artifact effects,providing acceptable diagnostic image quality in coronary CTA for patients with high heart-rate,especially the right coronary artery with faster movement,as well as the low and medial heart rate.