A comparative study of true ECG-gating and virtual ECG-gating techniques in coronary CT angiography

LU Liyu; YI Dongna; ZHOU Changsheng; TAN Yunze; ZHANG Longjiang; TANG Chunxiang

doi:10.19300/j.2025.L22500

Abstract：Objective To compare the clinical value of true electrocardiogram(ECG)-gating versus virtual ECG-gating in coronary computed tomography angiography(CCTA).Methods A total of 108 patients with suspected coronary artery disease undergoing CCTA were prospectively enrolled.Because switching between the two gating modes required additional time,participants were alternately assigned by the examination date to the true ECG-gating group(n=54)and the virtual ECG-gating group(n=54).Scans were performed on a United Imaging uCT 960+wide-detector CT.Examination time and radiation dose were documented.Using the American Heart Association 18-segment model,5-point subjective image quality scores were obtained,and coronary artery CT attenuation values,signal-to-noise ratio(SNR),and contrast-to-noise ratio(CNR)were measured.For patients who underwent invasive coronary angiography(ICA)within 30 days after CCTA,diagnostic concordance was assessed with ICA as the gold standard,with subgroup analysis by scanning mode.Continuous variables were compared using the t-test or Mann-Whitney U test,and categorical variables with the chi-square test.Receiver operating characteristic(ROC)curve analysis was used to evaluate diagnostic performance.Results In the virtual ECG-gating group,the distal left circumflex artery(LCX)CT attenuation,SNR,and CNR,as well as the subjective image quality score of the posterior descending branch of the right coronary artery,were superior to the true-gating group(all P＜0.05).No statistically significant differences were found for other image quality parameters between groups(all P＞0.05).Compared with the true-gating group,the virtual ECG-gating group had a 20.5％higher effective dose[3.99(3.77,4.28)mSv vs.3.31(2.91,3.75)mSv,P＜0.001],a 24.7％shorter total examination time[(3.62±0.34)min vs.(4.81±0.54)min,P＜0.05],and a 61％shorter positioning time[(0.76±0.19)min vs.(1.95±0.36)min,P＜0.05],but a 14.6％longer image reconstruction time[(48.06±7.18)s vs.(41.93±8.90)s,P＜0.05].In the ICA-validated subgroup,diagnostic concordance rates were 79.17％in the true ECG-gating group and 92.86％in the virtual ECG-gating group;the difference in diagnostic performance was not statistically significant(AUC:0.792 vs.0.854,P＞0.05).Conclusions Virtual ECG-gated CCTA significantly improves efficiency while maintaining image quality and diagnostic performance,with a slight increase in radiation dose.It is recommended for time-sensitive clinical scenarios,with adherence to dose-optimization principles.