CT Perfusion Imaging:Evaluating The Therapeutic Efficacy Of Hepatocellular Carcinoma After TACE

Part One Application of 3D-rigid registration for quantitative analysis of CT perfusion of the liverObjective:To investigate the value of motion correction by 3D non-rigid registration in improving the image quality and accuracy of quantitative analysis of CT perfusion of the liver.Materials and Methods:According to clinical needs,thirty-five patients with hepatocellular carcinoma treated by TACE(men,n=46;women,n=14,the ratio of males to females,3.38:1;age range,28~77 years;average age,55.52 +11.75 years.)underwent CT perfusion imaging with GE Revolution CT from October 2017 to October 2018 were prospectively selected in this study.Informed consent was obtained from all participants before the examination.All the images were analyzed on the workstation of ADW4.7 and image motion correction was performed using CT Perfusion 4D-Dynamic Registration software.The time-concentration curve of abdominal aorta and portal venous was measured and All the quantitative parameters including Blood flow(BF),blood volume(BV),mean transit time(MTT),time to peak(TTP),capillary permeability surface area product(PS),Hepatic artery fraction(HAF),positive enhancement integral(PEI),maximum rise slope(MSI),arrival delay time of contrast agent(IRF T0),peak transit time of pulse residual function(Tmax)of lipiodol sparse area or defect area after embolization of focal area of hepatocellular carcinoma and nomal liver parenchyma before and after motion correction were obtained and compared on the CT Perfusion 4D-Liver Tumor.Diffbrences of the time-concentration curve of abdominal aorta and portal venous as well as the image quality before and after correction were compared.Paired t tests or wilcoxon rank sum test was used to compare the differences of perfusion parameters before and after image correction.Chi-square test was used to evaluate the subjective score of image quality.Results:After 3D motion correction,the time—density curves of abdominal aorta and ponal vein became smoother with less fluctuation.The BF?BV?MTT?TTP?PS?HAF?PEI?MSI?IRF T0 and Tmax values of HCC after motion correction were lower than those before correction.There were significant differences in BF?BV?TTP?PS ? HAF ? PEI ? MSI and IRF T0 values before and after motion correction(P<0.05)whereas the difference between the two MTT and Tmax values were not significant(P>0.05).The values of BF?BV?TTP?PS?HAF?PEI?MSI and IRF T0 in nomal liver parenchyma after motion correction were significantly lower than that before motion correction(P<0.05).There was no significant difference between the two MTT and Tmax values(P>0.05).The subjective score of the corrected image was significantly higher than that of the pre-corrected image,and there was a statistical difference between them(P < 0.05).Conclusion:3D non—rigid registration has high value in the application of abdominal motion organs.It can significantly reduce motion anifacts and can improve the quality of CT perfusion image and the accuracy of the quantitative parameters of CT perfusion of the liver.Part Two CT Perfusion imaging: Evaluating the efficacy of hepatocellular carcinoma after TACEObjective:To investigate perfusion CT and conventional CT in the diagnosis of residual or recurrent disease after transcatheter arterial chemoembolization(TACE)are compared to analyze their value.Materials and Methods:Conventional enhanced CT(arterial phase and portal phase)examinations were performed in patients included in the first part of the study,and digital subtraction angiography(DSA)examinations were performed at intervals of 3-5 days.Using the corrected perfusion data in the first part,quantitatively analyze the relationships of perfusion parameters of the residual or recurrent lesions and surrounding normal 1iver tissue,including BF,BV,MTT,PS and HAF.The statistical method use paired t-test,when P<0.05,it is thought that the difference is statistically significant.Meanwhile,the trend of TDC between residual or recurrent lesions and normal liver parenchyma was compared.The residual or recurrence of the lesions after TACE operation is determined by liver dual phase enhanced scanning.DSA angiography results are taken as the gold standard to calculate the diagnostic sensitivity,specificity,positive predictive value and negative predictive value of conventional CT and CT perfusion.Differences in peak time of TDC in residual or recurrent focus,abdominal aorta and background hepatic parenchyma were analyzed by variance analysis of multiple sample mean.Results:47 lesions were evaluated in 35 patients,43 residual or recurrent lesions were found in CT perfusion.1.The perfusion parameters of the normal liver,BF was 145.39±133.83(ml/100g/min),BV was 21.57±6.01(ml/100g),MTT was 16.73±8.67(s),PS was 17.69±16.75(ml/min/100g),HAF was 0.14±0.22;The residual or recurrent lesions perfusion parameters in HCC after TACE as follow,BF was 210.08±188.26(ml/100g/min),BV was 33.45±8.54(ml/100g),MTT was 12.56±6.59(s),PS was 28.53±14.68(ml/min/100g),HAF was 0.64±0.23.There was a significant difference between two groups(P<0.05).BF?BV?HAF?PS of the residual or recurrent lesions were significantly higher than that of the norma I liver tissue,MTT of the the residual or recurrent lesions was significantly lower than that of the normal liver tissue.2.DSA angiography results are taken as the gold standard to compare conventional CT with hepatocellular carcinoma after TACE operation.The diagnosis sensitivity is 76.7%,the specificity is 50.0%,accuracy is 74.5%,the positive predictive value is 94.3%,the negative predictive value is 16.7%,and the kappa value is 0.14.The CT perfusion of the diagnosis sensitivity is 95.3%,the specificity is 75.0%,accuracy is 93.6%,positive predictive value is 97.6%,negative predictive value is 60.0%,,and the kappa value is 0.63.The CT perfusion were higher than those of conventional CT.3.By comparing residual or recurrent lesions and normal 1iver tissues through the peak enhancement time of the time—density curve,the residual or recurrent lesions peak time of the enhancement was 19.47±3.06(s),normal liver tissues peak time of the enhancement was 49.35±4.85(s),there was a significant difference between them(P<0.05).The residual or recurrent lesions showed a rapid rise and down,the enhancement of lesions in the arterial phase reached the peak,then decreased:the enhancement of normal liver tissues increased slowly and reached the peak in the venous phase.Conclusion:CT perfusion parameters can quantitatively and objectively analyze the microvascular perfusion in residual or recurrent hepatocellular carcinoma after TACE.The CT perfusion maps can directly find tumor lesions:Compared with conventional contrast enhanced CT,CT perfusion imaging has higher reliability and detection rate of residual or recurrent lesions of hepatocellular carcinoma after TACE.