体素内不相干运动(IVIM)和血氧水平依赖(BOLD)评估兔肝热缺血再灌注损伤:与CT灌注成像(CTPI)对照研究

IVIM and BOLD in the assessment of warm hepatic ischemia reperfusion injury in rabbits:comparison with CTPI

目的:探讨体素内不相干运动(IVIM)和血氧水平依赖(BOLD)反映兔肝热缺血再灌注损伤(WIRI)时微循环变化的敏感性及准确性。方法:30只新西兰健康成年雄兔随机分为G0组(对照组)、G1组和G2组(热缺血时间分别为40 min、60 min),行IVIM、BOLD和CTPI检查。取静脉血和冻存肝组织检测实验室指标,新鲜肝组织行病理学检查。采用单因素方差分析、相关分析和受试者工作特性曲线(ROC)进行统计学分析。结果:多组间各参数差异均有统计学意义(P<0.05);且随着热缺血时间延长,灌注相关扩散系数(Dfast)、灌注分数(PF)降低,表观自旋-自旋弛豫率(R2*)、肝动脉灌注指数(PI)升高,肝动脉灌注量(HAP)、肝门静脉灌注量(HPP)先升高再降低。相关性分析显示Dfast与PI,PF与PI、HAP均呈负相关(P均<0.05);Dfast、PF、R2*、HAP、PI均与谷丙转氨酶(ALT)、谷草转氨酶(AST)相关(P<0.05)。评价有无WIRI以及WIRI程度时,IVIM的诊断效能均高于BOLD,且与CTPI无统计学差异(P>0.05)。结论:IVIM无电离辐射、无需对比剂即可较好地反映肝WIRI时组织微循环变化情况。

Objective:To investigate the sensitivity and accuracy of intravoxel incoherent motion(IVIM)and blood oxygen level dependence(BOLD)in reflecting microcirculation changes in rabbits with hepatic ischemia reperfusion injury(WIRI),and to compare the diagnostic performance with CT perfusion imaging(CTPI).Methods:Thirty healthy adult New Zealand male rabbits were randomly divided into group G0(control group),group G1 and G2(the times of warm ischemia were 40mins and 60mins,respectively).IVIM,BOLD and CTPI examination were performed respectively.Statistical analyses were evaluated by one-way analysis of variance(ANOVA),correlation analysis and the receiver operating characteristic(ROC)curve.Results:There were statistically significant differences in the parameters among all groups(all P<0.05).Pseudodiffusion(Dfast)and perfusion fraction(PF)decreased,while apparent relaxation rate(R2*)and perfusion index(PI)increased,hepatic arterial perfusion(HAP)and hepatic portal perfusion(HPP)increased and then decreased with the prolonged warm ischemia times.Correlation analysis showed that PF was negatively correlated with PI or HAP as well as Dfast and PI(all P<0.05);Dfast,PF,R2*,HAP,PI were correlated with alanine aminotransferase(ALT)or aspartate aminotransferase(AST)(all P<0.05).The diagnostic performance of IVIM was higher than that of BOLD when evaluating the presence and the degree of WIRI,and there was no difference between IVIM and CTPI(P>0.05).Conclusion:Compared with CTPI,IVIM can reflect the changes of microcirculation during WIRI without ionizing radiation and contrast agent.