Primitive Study And Analysis Of Accuracy In MSCT About Two Hemodynamic Measurements-Deconvolution Arithmetic And Maximum-slope Method

(part 1) A method to test the accuracy of deconvolution arithmetic in CT perfusion measure — 30 cases of renal cortex perfusion provided to analyse.objective to test the accuracy of results drawn by deconvolution arithmetic inperfusion measure with CT.Method 30 healthy adults were chose at random to be scanned renal cortex byCT(selecting the level of the left renal vein),using deconvolution arithmetic tocalculate perfusion parameters. According to the parameters, we deduced theenhanced TDC of renal vein, comparing the results with actual TDC of renal vein andcalculating the decisive coefficient R~2, evaluating the anastomosis degree. Statisticwork was done in the software of MS excel2000.Results the anastomosis degree between theoretical and actual TDC of renal vein ishigh ,the 95% confidence interval of the mean of R~2 is 0.85-0.91.Conclusion deconvolution arithmetic is a kind of accurate arithmetic method intissue perfusion measure with CT.(part 2) Accurate analysis and improvement of maximum-slope method in CT perfusion in the condition of low injection velocity —40 cases of bilateral renal cortex perfusion acquiredto analyse.Objective: to analyse the accuracy of maximum-slope method in the condition of low injection velocity and to find out an efficient way which can improve its accuracyMethod: 40 cases of healthy adults were classified into two groups at random, injecting contrast medium with 4ml/min/ml and 2ml/min/ml respectively, and then scanned bilateral cortex of kidney with MSCT. Maximum-slope method, improved maximum-slope method and deconvolution arithmetic were used to measure the perfusion parameter of renal cortex respectively. We then evaluated the accuracy of maximum-slope method and improved maximum-slope method according to the standard of deconvolution arithmetic (SAS6.12, F test, a=0.05) . Result: the maximum-slope method can underestimate the volume of tissue blood flow under the condition of low injection velocity, the lower the injection velocity was applied, the higher the extent of underestimate was. There were not significant deviation between the improved maximum-slope method and deconvolution arithmetic (/?<0.05).Conclusion: the improved maximum-slope method can be used to measure the MSCT tissue perfusion approximately in the condition of low injection velocity.