Application Value of Prospective ECG-gated 256-slice CT Coronary Angiography

Objective To explore the application value and limitation of prospective ECG-gated 256-slice CT coronary angiography by comparing image quality and patient radiation dose received by prospective ECG-gated scan with those obtained by retrospective ECG-gated scan.Methods A total of 193 cases were collected in this study.90 cases accepted prospective ECG-gated 256-slice CT coronary angiography(group A) and 103 cases accepted retrospective ECG-gated scan as a contrast group(group B).The CT dose index of volume,length of scan field were recorded immediately after scan and the dose length product and effective radiation dose(ED) were calculated.Post processing methods included volume rendering,curved planar reconstruction and multiplanar reconstruction.Each coronary segment was scored according to the post-processed image quality.Results The mean ED in group A with an average heart rate of 69 bpm was(4.11±1.36) mSv and that in group B with an average heart rate of 78 bpm(12.10±5.62) mSv.The evaluable rate in group A was 94.1% and that in group B was 93.6%.There was statistically significant difference in the mean ED(P 0.05),but there was no statistical difference in the evaluable rate(P 0.05) between group A and group B.Conclusion Prospective ECG-gated 256-slice CT coronary angiography could keep satisfactory image quality and reduce radiation dose.It should be used in clinic at the most if the heart rate adaptive.