| Objects: To evaluate the ability of conventional and double low coronary CTA combined with Iterative Model Reconstruction(IMR)to demonstrate coronary stent phantom.Methods: Eighteen stent of different materials were selected and placed in simulated artificial coronary arteries.The prospective ECG-gated scan of 256-slice CT was performed with different tube voltage(100KV and 80KV),different concentration of contrast agent(12.85 mg I/ml and 6.59 mg I/ml)and different reconstruction algorithm,which is divided into three groups: conventional i DOSE4 group(100k V+12.86 mg I/ml),conventional IMR group(100k V+12.86 mg I/ml)and “double low” IMR group(80k V+6.58 mg I/ml).Image quality of the above three groups are evaluated with subjective scoring and objective indicator.The objective indicator includes image noise,signal-to-noise ratio,artificial lumen narrowing and attenuation.Results: The subjective scoring,image noise,signal-to-noise ratio,artificial lumen narrowing and attenuation of the three groups images were statistically significant(all P<0.05).Subjective scoring were the highest in the conventional IMR group and significantly higher than the other two groups.The conventional IMR group shows the lowest image noise and the highest signal-to-noise ratio compared with the double low IMR group and the conventional i DOSE4 group,which was significantly superior to the other two groups;the conventional IMR group shows the smallest artificial lumen narrowing and attenuation,which was significantly better than the conventional i DOSE4 group.Conclusions: Compared with conventional i DOSE4 group,the overall image quality of the conventional IMR group was the best,which significantly improved the imaging ability of coronary stents,followed by the double low IMR group,but having advantages in reducing the dose. |
