Relations between CT perfusion parameters and degree of hepatic ischemia reperfusion injury in a rabbit model

Abstract

Objective To observe the changes of hepatic CT perfusion parameters and their correlation with serum aspartate transaminase( AST),alanine transaminase(ALT) and alkaline phosphatase (ALP) in a rabbit hepalic ischemia reperfusion injury (IRI) model.Methods Hepatic IRI was produced in rabbits by inducing left liver lobe ischemia (60 min) followed by 6 h,12 h and 24 h reperfusion (6 rabbits were used for each reperfusion interval ).Additional 6 rabbits were served as sham-operatedcontrols.All the rabbits were scanned with a dynamic iCT protocol.Blood samples were taken from the superior mesenteric vein to measure the levels of serum amylase (ALT,AST,and ALP) in various groups,and liver samples were taken for histological examinations after scanning.One-way analysis of variance (ANOVA) was used to determine differences between groups.The correlations of CT perfusion parameters with serum levels were analyzed using Pearson correlation coefficient.Results Heterogeneity of CT perfusion patterns appeared in the 6 h groups,which presented as low enhanced area [ ( 25.1 ± 9.3 ) ml · 1min-1 · 100mg-1].In reduced perfusion regions of IRI group,HAP of 12 h IRI group [ ( 19.5 ± 13.6) ml · min-1 · 100 mg-1],24 h IRI group [(8.0+2.7) ml · min-1 · 100 mg-1 ],HPP of 6 h IRI group [(10.8±5.5) ml · min-1 · 100 rng-1],12 h IRI group [(14.4±5.2) ml · min-1 · 100 mg-1],24 h IRI group [(7.8±3.3) ml · min-1 · 100 mg-1] and TLP of 6 h IRI group [(35.9 ±14.0) ml ·min-1 · 100 mg-1 ],12 h IRI group [ (33.9 ± 16.1) ml · min-1 · 100 mg-1 ],24 h IRI group [ (16.0 ±5.5) ml · min- 1 · 100 mg-1 ] were lower than those of sham group [ HAP (21.2 + 10.5 ) ml · min-1100mg-1,HPP(63.5±24.0) ml · min-1 · 100 mg-1,TLP (81.4±24.8) ml · min-1 · 100 mg-1](F=8.376,25.950,16.925,P＜0.01).However,HPI of 6 h IRI group [(65.9±3.9)％],12 h IRIgroup [ (54.2 ± 16.7)％ ],and 24 h IRI group [ (48.9 ± 10.0)％ ] were higher compared to sham group [ ( 24.1 ± 7.5 ) ％ ] ( F =43.664,P ＜ 0.01 ).But,the perfusion parameters in the relatively normal area of IRI groups showed decline compared with sham group.The levels of AST,ALT and ALP in IRI groups were significantly higher than those in the sham group ( P ＜0.05).In poorly enhancing tissues,TLP and HPP of IRI groups were inversely correlated with AST and ALP respectively ( P ＜ 0.01 ),and HPI was closely related to the increase of AST ( r =0.751,P ＜ 0.01 ).Conclusion These results demonstrate CT perfusion is sensitive to detect the hemodynamic changes.Perfusion parameters are closely correlated to the degree of liver injury in the rabbit IRI model. Key words: Reperfusion injury; Tomography, X-ray computed; Comparative study