Feasibility Study On Triple Rule-out Computed Tomographic Angiography With Low Dose Of Contrast Agent And Radiation

Objective: To explore the feasibility for Triple-rule-out computed tomographic angiography with lower concentration of contrast agent and lower tube voltage in clinical.Methods: This experiment adopts a prospective research method.Planned to choose the patients who meet the inclusion criteria accepted the Triple-rule-out computed tomographic angiography at the First Hospital of Zibo from September 2014 to August 2016.According to the sequence of visits,the patients were divided into group A(270mg I/ml of iodixanol,100 k V)and group B(320mg I/ml of iodixanol,120 k V).Using Philips Brilliance 256-layer i CT with automatic tracking technology for contrast agent density and auto-triggered scanning in the area of interest,Extended Brilliance Workspace(EBW)post-processing workstation with CT machine.The amount of contrast agent was calculated based on 1 ml/kg.Set a high-pressure syringe contrast agent bolus rate of 5ml/s.After the contrast agent bolus,bolus 40 ml saline at the same rate.Two boluses are consecutive and there is no time interval.Set the tube speed 0.27s/r,pitch 1.0,collimation 128×0.625 mm,matrix 512×512,field of view 450 mm,reconstruction thickness 0.90 mm,interval 0.45 mm,iterative algorithm i Dose4 Level.Scan the positioning film first,and then perform calcification integral scan.The retrospective ECG gating technique is used for the formal scan.The level of the monitor is the descending aorta of the tracheal carina.The auto-triggered scan monitoring threshold is 100 Hu,and the scan range is 2cm above the upper edge of the aortic arch.2cm to the foot of the heart.Record and analyzed the Age,heart rate,height,weight,BMI,scan length,contrast agent dose,effective dose,image CT values,image of noise,signal to noise ratio,contrast to noise ratio and overall image quality scores.Results:There were not significantly different(P>0.05)between the group A and the group B in the physical data.There were significantly different(P<0.001)between the group A and the group B in the contrast agent dose.There were significantly different(P <0.001)between the group A and the group B in the effective dose.There were not significantly different(P>0.05)between the group A and the group B in the image CT values.There were not significantly different(P>0.05)between the group A and the group B in the image of noise.There were not significantly different(P>0.05)between the group A and the group B in the signal to noise ratio.There were not significantly different(P>0.05)between the group A and the group B in the contrast to noise ratio.There were not significantly different(P>0.05)between the group A and the group B in the overall image quality scores.Conclusion: On the premise of guarantee the quality of image,Combined use of lower concentration of contrast agent and lower tube voltage method for TRO CTA can effectively reduce the contrast agent dose and radiation dose.It is worth clinical promotion.