CT灌注成像在研究大鼠微小肝转移癌血供中的作用

背景与目的:肝脏是转移性肿瘤的好发部位,尤其是胃肠道肿瘤易转移到肝脏。肝转移癌的早期发现对其诊治和预后至关重要。本研究旨在使用多层螺旋CT灌注成像技术研究大鼠Walker-256微小转移性肝癌的血流动力学变化。方法:22只经脾脏注入Walker-256(细胞含量2×107)制备成肝脏微小转移癌的大鼠为实验组;10只大鼠经脾脏注入等量生理盐水为对照组;实验组中随机选取10只注射瘤细胞前的大鼠作为空白自身对照组。CT灌注扫描后用斜率法计算得到参数包括:肝动脉灌注量(hepaticarterialperfusion,HAP)、门静脉灌注量(portalveinperfusion,PVP)、肝灌注指数(hepaticperfusionindex,HPI)、总肝灌注量。病理学检查HE染色证实转移癌的存在。结果:实验组中有19只大鼠发现转移灶,直径0.5～6.6mm。各项参数值组间比较:实验组大鼠HAP[(97.67±31.42)ml·min-1·(100ml)-1],明显高于对照组[(43.35±17.39)ml·min-1·(100ml)-1]和空白组[(40.77±18.91)ml·min-1·(100ml)-1],差异具有显著性(F=47.84,P<0.0001);对照组和空白组之间差异无显著性。实验组PVP[(295.49±61.85)ml·min-1·(100ml)-1]明显低于对照组[(385.7±71.25)ml·min-1·(100ml)-1]和空白组[(362.73±78.56)ml·min-1·(100ml)-1],差异具有显著性(F=14.10,P<0.0001),对照组和空白组差异无显著性。总肝灌注量组间比较,三组之间没有差异(F=1.39,P=0.255)。结论:大鼠微小肝转移癌表现为肝动脉灌注量的增加和门静脉灌注量的降低。CT灌注成像技术可以用来评价肝脏的血流动力学变化,对于早期诊断肝脏转移癌具有潜在的临床应用价值。

Effect of perfusion CT scan on hepatic hemodynamic changes in rats with liver micrometastases

BACKGROUND & OBJECTIVE: Hepatic metastases are common for patients with malignant tumors, especially for the gastrointestinal malignancies. Early diagnosis confers better prognosis. This study was designed to investigate the hepatic hemodynamic changes by multi-slice helical perfusion CT in rats with liver micrometastatases of Walker-256 tumor cells. METHODS: Liver micrometastatases were produced in 22 SD rats by injecting 2 x 10(7) Walker-256 cells into the spleens. The ten experimental control rats were injected with normal saline solution. Ten rats were randomized into empty self control group from the experimental group before injecting tumor cells, which were studied by CT perfusion technique before being injected tumor cells. The time-density curves of the aorta, portal vein, and liver were used to calculate liver perfusion parameters by gradient method designed for the dual blood supply. These liver perfusion parameters were hepatic arterial perfusion (HAP), portal vein perfusion (PVP), hepatic perfusion index (HPI) and total hepatic blood flow. All the parameters were compared between the groups. H&E staining method was used to confirm the micrometastases pathologically. RESULTS: In the experimental group, 19 rats were found with micrometastases, of which the diameter was 0.5 mm to 6.6 mm. HAP was (97.67+/-31.42) ml x min(-1) x (100 ml) (-1) in metastasis group, and (43.35+/-17.39)ml x min(-1) x (100 ml) (-1) in control group, and (40.77+/-18.91) ml x min(-1) x (100 ml) (-1) in empty self control group. PVP was (295.49+/-61.85) ml x min(-1) x (100 ml) (-1) in metastasis group, and (385.7+/-71.25) ml x min(-1) x (100 ml) (-1) in control group, and (362.73+/-78.56) ml x min(-1) x (100 ml) (-1) in empty self control group, It was found that the HAP was higher in the rats with micrometastases than in those of the empty control group and also those of control group (F=47.84, P<0.000,1). While the PVP was lower in the rats with micrometastases than in those of the two control groups (F=14.10, P<0.000,1). For the total hepatic blood flow, no significant difference was found among the three groups (F=1.39, P=0.255). CONCLUSION: Higher HAP and lower PVP was noted in the rats with micrometastases. Perfusion CT technique can be used to evaluate the hepatic hemodynamic changes and thus has a potential clinical value for early diagnosis of liver micrometastases.