Feasibility And Clinical Application Of Prospectively Electrocardiographically-gated Transverse Dual-source CT Coronary Angiography

Coronary artery CT angiography has become the main examination of coronary artery disease,especially,the introduction of dual-source CT has shown a wide application in all patients[with a stable heart rate(HR) and without contraindication of coronary artery angiography]without controlling HR because of higher temporal resolution.Retrospectively ECG-gated helical(RGH) DSCT coronary angiography has a higher radiation dose because of small collimation and exposure in entire R-R interval.Prospectively ECG-gated transverse(PGT) DSCT coronary angiography has a substantial reduction of radiation dose because radiation is only administered at predefined time points of the cardiac cycle, rather than the entire R-R interval.The exactly definite of the time points of the cardiac cycle is the key influencing factor of PGT.PGT DSCT(2008 G) has partial overlapped data,as the center to predefined time points,plus or minus 10%. On the base of DSCT(2008 G),can prospectively ECG-gated transverse be used for all patients who with stable heart rate,without contraindication of CT coronary artery angiography,and got the similar accuracy of gold standard-SCAG? It has been focused by radiologists.We studied the feasibility and clinical application of prospectively ECG-gated DSCT coronary angiography.①Explore the feasibility of prospectively ECG-gated DSCT coronary angiography.Methods One thousand one hundred and eighty-three patients[Body mass index(BMI):23-25 kg/m~2,with stable HR,and average HR,77.7(beats per minute) bpm±5.8 bpm(standard deviation),range from 45 bpm to 125 bpm]with suspected or known coronary artery disease underwent retrospectively ECG-gated helical DSCT coronary angiography.Grouping them into 10 groups(A—J) according to the average HR of scanning.Images were reconstructed from 29%to 80%of the R-R interval in 3%increments.Two independent readers assessed the overall image quality on a five-point scale and determined the optimal reconstruction windows of each coronary segment and the ranges.Coronary arteries were segmented according to the guideline of the American Heart Association(AHA).The degree of inter-observer agreement was determined by Kappa statistics.Then analyze the agreement of the optimal reconstruction windows in the same group.Results The optimal construction windows in 9529 segments out of 9562 segments in group A,B,C,D were concentrated in 71%,ranged from 65%—77%. The optimal construction windows in 3272 segments out of 3343 segments in group H,I,J were concentrated in 41%,ranged from 32%—50%.The image quality assessment in 3343 segments in 232 patients have a high inter-observe agreement(Kappa =0.883).Conclusion The optimal reconstruction windows of patients with stable HR(≤75 bpm and≥91 bpm) were concentrated in 71%,ranged from 65%-80%, and in 41%,ranged from 32%—50%,respectively.The prospectively ECG-gated DSCT coronary angiography can be used in patients with stable HR(≤75 bpm and≥91 bpm) in abstract.②To explore the clinical application of prospectively ECG-gated transverse DSCT coronary angiography.Methods Two hundreds patients[Body mass index(BMI):23-25 kg/m~2,122 patients(average HR≤75 bpm),78 patients(average HR≥91 bpm)]with suspected or known coronary artery disease underwent prospectively ECG-gated transverse DSCT coronary angiography,among them,30 patients underwent selectively coronary angiography(SCAG),grouping them into 2 groups according to the average HR of scanning.Group A(17 cases,HR≤75 bpm),group B(13 cases, HR≥91 bpm),the DSCTA results were compared with SCAG.Then,calculate the accuracy of patients in each group and evaluate the agreement of accuracy between DSCTCA and SCAG by Kappa statistics.Accuracy between two groups was calculated byχ~2 test.Calculate the average effective radiation dose of the 30 patients.Results In group A,seventeen patients underwent both DSCT coronary angiography and SCAG,among 255 segments of 17 patients,105 lesion sites of 70 segments were diagnosed stenosis or obstruction,of them,95 lesion sites were confirmed by SCAG.The accuracy of DSCTCA was 90.48%.The agreement of two methods have a high agreement(Kappa =0.853).In group B,13 patients underwent both DSCT coronary angiography and SCAG,among 195 segments of 13 patients,73 lesion sites of 57 segments were diagnosed stenosis or obstruction, of them,65 lesion sites were confirmed by SCAG.The accuracy of DSCTCA was 89.04%.The agreement of two methods have a high agreement(Kappa =0.835). There was no significant difference(χ~2=0.098,p＞0.05) between the accuracy of two groups.The effective radiation dose of 30 patients was 3.67±0.43 mSv.Conclusion Compared with SCAG,prospectively ECG-gated transverse DSCT is a valuable examination to detect and diagnose coronary artery disease with a low dose coronary angiography.The accuracy of the DSCT is approximate to the SCAG.There was no significant difference between the accuracy of two groups.