Industrial CT Performance Test And Model Phantom Design

X-ray has been swiftly applied to security,medical and industrial nondestructive testing since X-ray has been discovered.To a large extent,the image quality of X-ray imaging equipment is restricting its development.To standardize image quality has become a hot topic in today's research.China develops the relevant national standard for micro-dose X-ray security equipment,medical CT and industrial CT imaging equipment,but lacking an unified calibration methods and standardized phantom,so that the X-ray image quality is in a state that cannot be traced.In order to study evaluation methods of X-ray image quality,the following contents were carried out by means of Industrial CT of NIM?National institute of metrology,China?.?1?To test the performance of industrial CT,including spatial resolution and density resolution.Spatial resolution testing methods include theoretical calculations,line-pair testing,and disk measuring methods;density resolution testing methods include liquid density phantom,and disk method.?2?In order to solve cupping artifacts that caused by the X-ray continuous spectrum's"hardening"phenomenon,doing research on samarium K fluorescence yield and purity.Researching the relationship between fluorescence quality and thickness of radiator Sm₂O₃ or secondary filter CeO₂ by simulating fluorescence instrument with MCNP program;the effects of X-ray tube voltage on the fluorescence yield were measured and analyzed;and fabricate the radiators of Au and Pb so that test monotonicity.?3?According to GB15208-2005 relevant provisions,manufacture test block for micro-dose X-ray security inspection system.The test block contains two aspects of image resolution and material differential.The image resolution is used to test the wire display resolution,useful penetration resolution,spatial resolution and simple penetration of the facilities.The material differential block is used to test performance of distinguishing material.?4?At present,the main domestic medical CT phantoms are mainly from The Phantom Laboratory in American and RTI Company in Swedish.Phantoms involve DSA-8 Plus,wire-type image quality indicators,dental phantom,and ALK-2°,X-11-DR.Analyzing and processing radiation image of phantom,and calculate Relative error.?5?The image quality of industrial CT is influenced by focal spot size,detector pixel size,reconstruction algorithm,magnification factor.It is difficult to evaluate 3D reconstructed images.Designing new type industrial CT phantoms to supplement the domestic related research.Through the above works on the X-ray image quality evaluation analysis to improve the domestic X-ray images QA,QC and industry specifications.