冠状动脉追踪冻结技术对不控制心率受试者CT冠状动脉成像质量的影响

Effect of snapshot freeze motion correction algorithm on image quality of coronary CT angiography without heart rate control

目的 评估冠状动脉追踪冻结技术（SSF）对不控制心率受试者CT冠状动脉成像质量的影响。方法 31例疑似冠心病行CT冠状动脉成像的连续患者,均未服任何控制心率药物。CT冠状动脉成像图像均使用标准算法及SSF 2种方法进行重建.由2名有经验的医师比较标准算法和SSF重建2种方法的图像质量及可判读性,并对每支冠状动脉及其各段血管水平进行图像质量评分,评分标准为Likert 4分。图像评分≥2分为具有可读性。对图像的可判读性行配对卡方检验,对图像质量评分行配对秩和检验。结果 图像的可判读性在使用SSF与标准算法重建之间比较,在受试者水平[分别为100.0％（31例）和64.5％（20例）,X2=9.09,P=0.002]、受试者的血管水平[分别为100.0％（124/124）和83.9％（104/124）,X2=18.05,P=0.001]及血管的节段水平[分别为99.0％（413/417）和89.2％ （372/417）,X2=35.56,P=0.001]差异均有统计学意义。左主干评分在2种算法之间差异无统计学意义[分别为（3.9±0.4）和（3.7±0.6）分,Z=1.89,P=0.059],前降支[分别为（3.3±0.7）和（2.9±1.0）分,Z=2.70,P=0.007]、回旋支[分别为（3.1±0.8）和（2.5±1.1）分,Z=3.23,P=0.001]及右冠状动脉[分别为（3.3±0.6）和（2.1±0.9）分,Z=4.60,P=0.001]评分在2种算法之间差异均有统计学意义,每段评分在2种算法之间差异亦有统计学意义[分别为（3.5±0.7）和（3.0±1.0）分,Z=10.31,P=0.001]。结论 与标准算法比较,SSF能够明显提高CT冠状动脉成像图像质量及可判读性。

Objective To assess the effect of snapshot freeze （SSF） motion correction algorithm on the image quality of coronary CT angiography （CCTA）.Methods Thirty-one consecutive patients underwent coronary CTA without heart rate control.All of the CCTA images were reconstructed by the means of both standard （STD） and SSF motion correction.Image quality and interpretability of STD and SSF reconstructions were compared.CCTA images were interpreted with Likert 4-points score system by two experienced radiologists.The image qualities were assessed on per-artery and per-segment level,and interpretability was performed on per-segment,per-artery,and per-patient levels.Comparisons of variables were performed with paired Wilcoxon rank sum test and paired Chi-square test.Results SSF reconstructions showed higher interpretability than STD reconstructions on per-patient [100.0% （31/31） vs 64.5% （20/31）,X^2 =9.09,P =0.002] and per-artery [100.0% （124/124） v s 83.9% （104/124）,X^2 =18.05,P =0.001] and per-segment level [99.0% （413/417） vs 89.2% （372/417）,X^2 =35.56,P =0.001].Image qualities were higher with the use of SSF than STD reconstructions on LAD [3.3 ± 0.7 vs 2.9 ± 1.0,Z =2.70,P=0.007],LCX [3.1 ±0.8 vs 2.5 ＆#177; 1.1,Z =3.23,P =0.001] and RCA [3.3 ±0.6 vs 2.1 ±0.9,Z =4.60,P =0.001],but they were similar on LM [3.9 ±0.4 vs 3.7± 0.6,Z =1.89,P =0.059].Image quality was higher with the use of SSF versus STD reconstructions on per-segment [3.5± 0.7 vs 3.0 ± 1.0,Z =10.31,P =0.001] level.Conclusions The use of SSF motion correction algorithm improves image quality and interpretability of coronary CTA without heart rate control.