To Evaluate The Effect Of The Third-generation Dual-source CT Virtual Monoenergetic Reconstruction Technique In Reducing Oral Metal Artifacts

Objective:To evaluate the effect of the third-generation dual-source CT virtual monoenergetic reconstruction technique in reducing metal artifacts.Methods:(1)Using the domestic pig simulate oral and maxillofacial environment of human in body,and making nickel-chromium metal crowns,and putting into the maxillary molars of the first,second and third teeth of the head respectively,and finally being scanned with dual-source CT.Images were reconstructed by using 8 algorithms,including the standard linearly blend(M＿0.6),FAST DE,and 6 virtual monoenergetic algorithms(40keV、70 keV、100 keV、130 keV、160 keV、190 keV)and Compareding the quality and artifacts.(2)Collecting 28 patients who underwent maxillofacial dual-source CT scan in Shanxi Provincial People’s Hospital and had metal implants in their oral cavity.Then,standard linear fusion(M＿0.6)and virtual single-energy image reconstruction(100keV,110 keV,120 keV,130 keV,140 keV,150 keV,160 keV)were performed for 8groups.Finally,the image reconstruction conditions and image quality evaluation methods were the same as before to further verify the results of animal experiments.Results:(1)animal group: The subjective scores of 130 keV and 160 keV images were significantly better than those of other groups(P < 0.01);There was no statistical difference in the CT value of masseter in the 130 keV image between the two levels(P >0.05).(2)Clinical group:The subjective score of the 130 keV group and the 160 keV group was better than that of the other groups(P < 0.01),and the mean value of the 130 keV group was higher than that of the 160 keV group(P < 0.01);There was no statistical significance in the CT value of lingual muscle in the 130 keV group between with and without artifacts.Conclusion:The third-generation dual-source CT virtual monoenergetic reconstruction technique can effectively reduce metal artifacts in the oral metal implants and obtain high quality reconstructed images,and the optimal imaging condition is 130 keV.