Impact of image quality with scan parameters and reconstruction algorithms in head dual-energy computed tomography angiography / 重庆医学

ABSTRACT

Objective To study the difference of image quality which based on different reconstruction in head dual‐energy computed tomography angiography (DECTA) scanning ,and evaluate the radiation dose which using different tube voltage in DEC‐TA .Methods An anthropomorphic head phantom with simulated arteries was used for DECTA scanning by different scan parame‐ters (tube voltage 80/140 kV and tube voltage 100/140 kV) ,the data was reconstructed with filtered back projection (FBP) and Si‐nogram Affirmed Iterative Reconstruction (SAFIRE) .The CT values with SD were measured and calculate to SNR and CNR ,the dose length product (DLP) was recorded and invert to effective dose .The image quality and radiation dose were evaluated in differ‐ent imaging condition .Results The image noise of SAFIRE reconstruction was lower than FBP reconstruction in same san parame‐ters .The increase of tube current‐time product from 100 mAs to 300 mAs ,it shows the characteristics of linear tendency .When it was on 260 mAs ,the image quality become stable .The difference between the two groups(80/140 kV ,100/140 kV)of SD of CT value by SAFIRE was significant (P0 .05) .The effective doses of group A (80/140 kV) was significantly lower than group B(100/140 kV) .Conclusion Using tube voltage of 80/140 kV combine with SAFIRE algorithm in head DECTA can ensure the image quality ,which can significantly reduce radiation dose .