CT灌注成像对缺血再灌注损伤中肝内门体静脉分流的评价

目的 探讨CT灌注成像（CTPI）在缺血再灌注（I/R）损伤中对肝内门体静脉分流的诊断价值。方法 选择12只成年犬,剖腹下经小隐静脉注射前列地尔（Lipo-PGE1）,剂量为1μg/kg,用药前1h和后5min同时采用CTP和电磁流量仪（EMBF）测量门静脉灌注量（PVP）,评价两种方法的相关性。21只成年犬随机分成3组：对照组、静脉用药组（IV组）、肠系膜上动脉用药组（SMA组）,每组7只。I/R模型建立方法为肝门阻断45min后再灌注60min。IV组和SMA组每只犬的Lipo-PGE1用量为1μg/kg、注射速度为0.05μg/（kg·min）,对照组每只犬的0.9%生理盐水（NS）用量为2mL/kg,肝门阻断前5min和再灌注60min后各用药1次。各组首次用药前30min及再次用药后30min依次行CTPI、门静脉测压和病理取材,对比分析I/R前后PVP、门静脉自由压（FPP）和病理学的变化。结果 CTPI与EMBF的PVP值接近且高度相关（r=0.87）,Lipo-PGE1用药后PVP明显增加。I/R后对照组、IV组、SMA组CTPI的PVP分别为：（0.22±0.06）、（0.26±0.06）、（0.38±0.11）mL/（min·mL）;EMBF的PVP分别为：（0.29±0.08）、（0.30±0.07）、（0.41±0.11）mL/（min·mL）,3组两种方法结果比较的差异均有统计学意义（t=-9.410,P=0.000）、（t=-11.711,P=0.000）、（t=-9.370,P=0.000）,其相差程度分别为31%、25%、8%。对照组I/R后FPP明显升高（P〈0.05）,而SMA组、IV组I/R前后变化不显著（P〉0.05）。I/R后对照组的肝组织结构欠清,肝细胞浊肿,肝窦内红细胞淤积,汇管区中性粒细胞浸润明显。SMA组的肝组织损伤明显改善,IV组的变化介于对照组和SMA组之间。结论 CT灌注成像能定量反映缺血再灌注损伤中肝内门体静脉分流的变化和药物治疗的作用。

Evaluation of CT perfusion imaging for the intrahepatic portal-systemic vein shunts on liver ischemia/ reperfusion injury

Objective To investigate the application of CT perfusion imaging （CTPI） for the intrahepatic portal sys temic vein shunts on liver ischemia/reperfusion injury. Methods Twelve adult dogs were injected with Lipo-PGE1 （1 μg/kg） via saphenous. CTPI and EMBF were performed before medication 1 h and after medication 5 min at laparotomy. The correlation of PVP using the two methods was analyzed. Twenty-one adult dogs were divided into three groups randomly： control group, IV group and SMA group, each ,group includes seven dogs. Animals were occluded porta hepatis 45 min and reperfused 60 min to establish I/R injury models. The dosage of Lipo-PGE1 was 1 μg/kg and rate 0.05 lxg/（kg·min） in IV and SMA group; 0.9% sodium chloride of 2 mL/kg was used in the control group. The administration was conducted before porta occlusion 5 min and after reperfusion 60 min, respectively. CTPI, free portal pressure measurement （FPP） and pathological sampling were performed in succession and compared before first administration 30 min and after second administration 30 min. Results PVP by CTPI and EMBF was similar and highly con＇elated （r=0.87）. PVP obviously increased after taking Lipo-PGE1 via vein. The PVP mL/（min·mL）] in control group, IV group and SMA group were 0.22±0.06, 0.26±0.06 and 0.38±0.11 by CTPI post-I/R and 0.29±0.08, 0.30±0.07 and 0.41±0.11 by EMBF, respectively. There was a significant difference in group comparison between two methods （t=-9.410, P=0.000）, （t=-I 1.711, P=0.000）, （t=-9.370, P=0.000）. The difference of PVP between two methods were 31%, 25%, 8% in three groups, respectively. FPP increased obviously after I/R than that in control group, but there were no significant differences between SMA and IV groups. Microscopically, the structure of liver was evidently vague, hepatocytes were cloudy swelling, erythrocytes stasis in hepatic sinusoid, and neutrophilic granulocyte predominately infiltrated portal area in control group. The liver injury was moderately improv