CT血管造影中回顾性心电门控螺旋扫描心电触发序列扫描技术诊断复杂性心律失常的准确性及辐射剂量比较

Accuracy and radiation dose of retrospective ECG-gated cardio helical scanning vs adaptive prospective ECG-triggered cardio sequence scanning techniques in diagnosing complex arrhythmia during CT angiography

目的观察CT血管造影(CTA)中回顾性心电门控螺旋扫描(RCH)、适应性前瞻性心电触发序列扫描(APCS)技术对复杂性心律失常的诊断准确性,并比较辐射剂量。方法选取本院120例复杂性心律失常患者,依据数字表法将其随机分为3组,各40例,A组采取APCS技术,依据改良绝对值完成全剂量扫描RR间期的预设;B组采取APCS技术,根据惯用相对值完成RR间期的预设;C组采取RCH技术。比较3组检查图像指标[血管CT值、对比噪声比(CNR)、信噪比(SNR)]、辐射剂量[CT容积剂量指数(CTDIvol)、剂量长度乘积(DLP)、有效剂量(ED)]、冠状动脉图像评分、可诊断节段。结果3组升主动脉及冠状动脉CT值、CNR、SNR比较差异无统计学意义(P>0.05);CTDIvol、DLP、ED为:A组<B组<C组,差异有统计学意义(P<0.05);A组冠状动脉图像评分明显高于其余2组(P<0.05),且B组明显高于C组(P<0.05);A组与B组右冠状动脉(RCA)可诊断节段明显多于C组(P<0.05),A组与C组左冠状动脉前降支(LAD)可诊断节段明显多于B组(P<0.05),总可诊断节段数与可诊断患者:A组>B组>C组(P<0.05)。结论相较于RCH,APCS可提高复杂性心律失常检查中冠状动脉图像质量,增加可诊断节段数及可诊断患者,提高诊断准确性,并减少辐射剂量,尤其是改良APCS技术,效果更显著。

Objective To investigate and compare the diagnostic accuracy and radiation dose of retrospective ECG-gated cardio helical scanning(RCH)vs adaptive prospective ECG triggered cardio sequence scanning(APCS)techniques in CT angiography(CTA)for complex arrhythmia.Methods A total of 120 patients with complex arrhythmia in our hospital were included and randomized into three groups(n=40 each)according to random number table.For group A,APCS was used to complete the preset of the full-dose scan RR interval based on modified absolute values;for group B,APCS was used to complete the preset of the RR interval based on customary relative values;for group C,RCH was used.The three groups were compared for imaging indicators[vascular CT value,contrast-to-noise ratio(CNR),signal-to-noise ratio(SNR)],radiation dose[CT dose index volume(CTDIvol),dose length product(DLP),effective dose(ED)],coronary image score,segments considered diagnostic.Results There were no significant differences in CT values,CNR and SNR of the ascending aorta and coronary arteries in the three groups(P>0.05).CTDIvol,DLP and ED were lowest in group A,followed by groups B and C from low to high,with significant difference(P<0.05).The coronary image score was significantly higher in group A than in the other two groups(P<0.05),and so was in group B than in group C(P<0.05).There were significantly more segments of right coronary artery considered to be diagnostic in groups A and B than in group C(P<0.05),and so were segments of left anterior descending branch considered to be diagnostic in groups A and C than in group B(P<0.05).The total number of segments considered to be diagnostic and diagnosable cases were highest in group A,followed by groups B and C from high to low(P<0.05).Conclusion Compared with RCH,APCS may lead to better quality of coronary imaging in patients with complex arrhythmia,increase the number of segments considered to be diagnostic and the number of diagnosable patients,improve diagnosis accuracy,and reduce radiation dose.The clinical benefits are even more significant with modified APCS techniques.