The Application Of256-slice CT Angiography In Diagnosis Of Acute Chest Pain

Purpose:To compare image quality and radiation dose in patients who underwent256-slice TRO CTA performed with prospective ECG-gated with image quality and radiation dose in patients who underwent256-slice TRO CTA performed with retrospective ECG-gated technique.Material and Methods:Sixty two patients who had low-risk acute chest pain and undergone CT angiography were selected. The enrolled patients were divided into2groups randomly. Thirty-one patients (group A) were performed with prospective ECG-gated CTA, and thirty-one patients (group B) were performed with retrospective ECG-gated CTA.(2) The subjective image quality and objective image quality were evaluated. The objective image quality was measured as signal-to-noise ratio [SNR] and contrast-to-noise ratio [CNR]. Then two blinded observers analyzed the image quality of the arteries independently. The subjective image quality was according to the5point scoring scale.(3) The radiation dose was also measured in both groups. The effective radiation dose [ED] was calculated using CT dose volume index [CTDIvol.], dose-length product [DLP]. Analyses were performed using the statistical software (SPSS, version16for Windows). A P value less than0.05were indicative of a statistically significant difference.Results:(1) Although the CT value of aortic artery in group B was lower than group A (384.31±9.25) Hu vs.(388.80±7.94) Hu, There was no significantly different between two groups (P=0.09). Although the CT value of pulmonary artery in group B was lower than group A (384.62±9.15) Hu vs.(388.06±8.25) Hu, There was no significantly different between two groups (P=0.12). Although the CT value of coronary artery in group B was lower than group A (384.25±9.09) Hu vs.(387.73±7.53) Hu, There was no significantly different between two groups (P=0.11). There was no significantly different between two groups, as mention to SNR, CNR, SI and BN. There was no significantly different between group A and group B (4.98vs.4.87P=0.73).(2) The radiation dose was found to be reduced by67.4%in group A compared with group B (6.45±0.39vs.19.76±1.12) mSv (P0.0001).Conclusion:ECG-gated256-slice CT angiography can evaluate the coronary artery, pulmonary artery and thoracic aorta through one examination, and make the diagnosis of these diseases. Use of256-slice CT coronary angiography performed with prospective ECG gating has similar subjective and objective image quality but67.4%lower radiation dose when compared with use of retrospective ECG gating.