The Application Value Of Different Reconstruction Method And Different Imaging Technology On Improved CTU Imaging Quality

Backgrouds and objective Since computed tomography urograpy(CTU)applied to clinical,become a important method of diagnosis of urinary system instead of the IVU and primary examination method in assessing patients with hematuria.However the beam-hardening artifacts of traditional CTU excretion period caused by the high concentration of iodine contrast,affectting the urinary system structure of anatomical structures and related lesions showed,and reduces the definition of the contrast medium surrounding tissues,influenced image quality seriouly.The research starting from reducing beam-hardening artifact by compareing the beam-hardening artifacts of the renal pelvis of the filter back projection reconstruction place(FBP),adaptive statistical iterative reconstruction(ASi R),GSI(85 ke V)and improved method CTU,exploring different imaging technology and image reconstruction methods in reducing the role of the CTU beam-hardening artifact,thereby improve the CTU image quality.Material and Methods 1.For conventional CTU,40 patients underwent GSI for exeretory phase after convention scan Then raw data were reconstructed with FBP and ASIR30% reconstruction algorithms for conventional CTU and 85 ke V for GSI.Thickness is 0.625 mm for all.All the data transferred to GE Workstation.2.For the 32 patients underwent improved method CTU with 64 layer spiral CT machine scan,data with FBP algorithm to reconstruction,thickness is 0.625 mm for all.All the data transferred to GE Workstation.Measured renal noise,contrast noise ration,signal to noise ration and evaluate the beam-hardening artifacts of renal calyx on the obvious of renal calyx and the continuity of ureter on the above image obtained by apopting the method of VR.MRP.MIP.CPR line urinary tract imaging postprocessing.Result The score of the BHA,tradtional FBP group,ASIR group,gemstone spectral and improved method group was 1.30±0.46,1.40±0.49,2.53±0.51 and 2.79±0.41(P<0.05);The noise of the renal of FBP,ASIR and GSI and improved method group was 40.25±7.80,33.84±6.92,19.89±5.22 and 29.36±6.98(P<0.05).Compared with FBP,the SD reduced by 16% and 51% and 27% in the image reconstructed with ASIR and gemstone spectral and improved method.The SNR of the FBP?ASIR ?gemstone spectral and improved method group was 3.88±0.77,4.69±0.94,5.51±1.21 and 6.88±2.02(P <0.05);Compared with FBP,the SNR increased by 21% and 42% and 77% in the image reconstructed with ASIR and gemstone spectral and improved method;The CNR of FBP,ASIR,gemstone spectral and improved method group was 8.19±1.35,9.87±1.64,11.36±1.60 and 12.50±3.17(P<0.05),Compared with FBP,the CNR increased by 21% and 39% and 52% reconstructed with ASIR and gemstone spectral and improved method;Improved method is superiority on continuity of ureter.Conclusion The improved method is superiority to other methods in reducing the BHA,and the next is GSI(85 ke V).The GSI is the most preponderant method in reducing SD,and the improved method and ASi R are also better.Improved method is superiority to other methods in the displaying the continuity of ureter.