Objective To explore the clinical value of monoenergetic technology of dual-source CT in removing the artifact of me-tallic fixation after the operation of lumbar spondylolysis.Methods 24 cases of patients with metallic fixation after operation of lum-bar spondylolysis were scanned by dual-energy CT.To reconstruct the imaging using monoenergetic and 3D Inspace software,obtain 50,80,110,140,170 keV five groups of images and the multi-planar reconstruction*(MPR),volume vendering(VR),maximum intensity projection(MIP)imaging in different conditions.The five groups image and average weighted 120kev image are evaluate by two senior radiologist.The quality score of five groups of images and the average weighted images are analyzed statistically using Kruskal-Wallis test.The clinical value of images in the optimal condition are evaluated by two senior department of orthopedics phy-sicians.The results of two radiologists and department of orthopedics physician are examined by kappa test to evaluate consistency. Results In all patients after operation,the case of 110keV images above 3 points is 24,the case of 80keV images above 3 points is 14,the case of of 140keV images above 3 points is 13,the case of weighted average 120kev images above 3 points is 8.Images in 110keV have the best quality (F=98.523,P<0.01).MPR,VR,MIP images are reconstructed in 110keV.The ratio of image which are excellent and have high clinical value is 86.1%,especially the ratio of MPR image is 100%.Conclusion Monoenergetic technology of dual-source CT has a higher clinical value in removing the artifact of metallic fixation after the operation of lumbar spondylolysis.Under the condition of 110keV the quality of images are best,the reconstructed images using MPR Technology have the best clinical value.

Objective To explore a method of forensic identification work in the non-linear length of the plane. Methods 10 soldering tin wires with different lengths were cut out accurately and the results were read as a control (direct reading method of steel ruler). Then the ten soldering tin wires with different lengths were randomly bent and then calculated by the method studied in this paper The length as a Pixel group, and two sets of data for statistical analysis. Results The difference between the results obtained by the Pixel method and those directly read by the ruler direct reading method was not statistically significant. Conclusion The Pixel method has obvious advantages over the traditional cotton method in measuring the non-linear length of the plane (such as scars and wounds). The calculated length is more accurate and easy to operate, making the forensic identification more accurate and convincing Adapt to the requirements of litigation, forensic identification in the good prospects.