兔肝缺血再灌注损伤CT灌注参数与肝损伤关系的研究

目的 观察兔肝缺血再灌注损伤(IRI)后CT灌注参数演变规律及与肝脏酶学天冬氨酸转氨酶(AST)、丙氨酸转氨酶(ALT)、碱性磷酸酶(ALP)]的相关性.方法 新西兰大白兔阻断肝左叶血供60 min后,恢复血供,按再灌注后行CT扫描的时间分为6、12、24 h IRI组以及假手术(sham)组(每组6只).各组分别行CT全肝灌注成像、肝酶学和病理检查.多组均数间差异性分析采用单因素方差分析,血中肝脏酶水平与CT灌注参数相关性采用Pearson相关分析.结果 在IRI后6h肝左叶开始呈现出灌注减低区；在低灌注的肝组织中,除6 h IRI组的肝动脉灌注量(HAP) (25.1±9.3)ml·min-1·100 mg-1]外,其余各IRI组HAP12 h IRI组(19.5±13.6)ml·min-1·100 mg-1、24 h IRI组(8.0±2.7)ml· min-1·100 mg-1]、HPP6 h IRI组(10.8±5.5)ml· min-1·100 mg-1、12 h IRI组(14.4±5.2)ml· min-1· 100 mg-1、24 h IRI组(7.8±3.3)ml·min-1·100 mg-1]、TLP6 h IRI组(35.9±14.0) ml· min-1· 100 mg-1、12 h IRI组(33.9±16.1)ml·min-1·100 mg-1、24 h IRI组(16.0±5.5)ml·min-1·100 mg-1]均低于sham组HAP、HPP和TLP分别为(21.2±10.5)、(63.5±24.0)和(81.4±24.8)ml·min-1·100 mg-1](F值分别为8.376、25.950、16.925,P值均＜0.01),而肝动脉灌注指数(HPI)6 h IRI组、12 h IRI组和24 h IRI组分别为(65.9±3.9)％、(54.2±16.7)％和(48.9±10.0)％]则高于sham组(24.1±7.5)％,F=43.664,P＜0.01]；而在灌注相对正常的肝组织中各灌注参数均呈下降趋势.各IRI组血清AST、ALT、ALP显著上升(P＜0.05).在IRI组中灌注减低肝组织CT灌注参数HPP、TLP分别与AST、ALP存在负相关(P＜0.01),而AST与HPI间存在正相关(r=0.751,P＜0.01).结论 CT灌注参数能够动态监测兔肝IRI后血流动力学,其灌注参数(HPP、TLP、HPI)与肝损伤的程度具有密切的相关性.

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

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.