64-detector row CT coronary angiography：clinical application of retrospective electrocardiographic gating technique combined with electrocardiographic editing

YU Ling-ming; YE Xiao-dan; ZHU Li; CHEN Qun-hui

Abstract：Objective To prospectively evaluate to what extent image quality in 64‐detector row computed tomographic (CT ) coronary angiography is a function of electrocardiographic editing and the image reconstruction technique used . Methods A total of 36 patients (14 men ,22 women ;mean age ,61 .0 years ± 9 .1) in department of radiology consecutive‐ly underwent multi‐detector row CT coronary angiography .Their electrocardiographic trigger points were proved to be in‐accurately or absent ,which caused unequal R‐R intervals .Image reconstruction was based on both before and after electro‐cardiographic trigger points editing .Reconstructed images were classified by artifacts as grades I ~ Ⅳ ,in which grades I~Ⅲ were considered to have diagnostic value .Results Among the total of 36 patients ,there were 521 and 528 segments of coronary arteries before and after electrocardiographic editing ,respectively .Before electrocardiographic editing ,images quality of grades Ⅰ ,Ⅱ ,Ⅲ ,Ⅳ were 133 (25 .5% ) ,162 (31 .1% ) ,120 (23 .0% ) ,106 (20 .3% ) ,respectively .It was 415 (79 .6% ) segments that with diagnostic value .After electrocardiographic editing ,images quality of grades Ⅰ ,Ⅱ ,Ⅲ ,Ⅳ were 439 (83 .1% ) ,70 (13 .3% ) ,8(1 .5% ) ,11(2 .1% ) ,respectively .It was 517 (97 .9% ) segments that with diagnostic value .There was significant difference between before and after electrocardiographic trigger points editing ( P<0.05) .Conclusion In multi‐detector row CT coronary angiography ,when inaccurately or absent electrocardiographic trigger points were found ,image quality could be improved by retrospective electrocardiographic gating technique combined with electrocardiographic editing techniques .