门静脉癌栓与门静脉血栓的多层螺旋CT影像研究

Analysis of multi-slice CT imaging features of portal vein cancer embolus and portal vein thrombosis

目的探讨肝硬化合并肝癌、门静脉癌栓患者和肝硬化合并门静脉血栓患者的癌栓与血栓的MSCT影像特点及病变解剖部位的差异。方法回顾性分析2011年5月-2016年5月北京大学深圳医院和2013年8月-2014年8月广东省海丰县彭湃纪念医院经临床诊断的18例肝硬化合并肝癌、门静脉癌栓患者（癌栓组）和12例肝硬化合并门静脉血栓患者（血栓组）的临床资料。所有患者行MSCT平扫，以及动脉期、门静脉期及延迟期3期增强扫描，并采用多平面重建（MPR）和5mm厚度最大密度投影（MIP）重建技术对门静脉行3D重建。观察门静脉癌栓和血栓的影像特征、分布情况及侧支循环血管形成情况，比较癌栓和血栓在平扫和增强扫描各时相的密度差异。结果癌栓组中，CT平扫12例呈低密度并血管增粗，6例呈等密度；CT增强扫描显示动脉期癌栓均呈不均匀强化、15例可见滋养血管影，门静脉期4例呈稍高密度、5例呈等密度、9例呈低密度，延迟期均呈低密度；18例门静脉癌栓均累及门静脉左或／和右支，仅6例累及门静脉主干。血栓组中，CT平扫3例呈等密度，3例呈低密度，6例呈稍高密度；CT增强扫描血栓均无强化，门静脉期及延迟期血栓部位无对比剂充盈；12例中，11例门静脉血栓累及门静脉主干，6例血栓延伸至左叶或／和右叶门静脉分支。门静脉癌栓和血栓在CT平扫和增强扫描的延迟期密度的差异均无统计学意义（P值均〉0．05），而增强扫描的动脉期和门静脉期，癌栓密度明显高于血栓，差异均有统计学意义（P值均〈0．05）。癌栓累及门静脉左或／和右支的概率明显高于血栓，而血栓累及门静脉主干的概率明显高于癌栓，差异均有统计学意义（P值均〈0．05）。结论结合MSCT平扫及3D重建技术，能客观显示肝硬化患者门静脉癌栓与门静脉血栓的影像特点及其累及范围，能为病变诊断提供客观依据，从而指导临床选择合适的治疗方案。

Objective To evaluate the difference of multi-slice spiral CT （MSCT） imaging features and the anatomical positions of portal vein cancer embolus and portal vein thrombosis involving in patients with cirrhosis. Methods Clinical data of 18 cases of liver cirrhosis complicated with hepatocellular carcinoma and portal vein cancer embolus and 12 cases of portal vein thrombosis confirmed by clinically from May 2011 to May 2016 in Peking University Shenzhen Hospital and from August 2013 to August 2014 in Haifeng Pengpai Memorial Hospital of Guangdong Province were retrospectively analyzed. The pre-contrast enhancement scanning, hepatic artery phase, portal venous phase and delay phase of MSCT were performed in all two group patients, all patients suffered from cirrhosis which were confirmed by clinical or laboratory. The three-dimensional （3D） imaging reconstruction technologies for portal vein included muhiplanar reconstruction（MPR） and 5 mm maximum intensity projection （MIP）. The imaging manifestations and distribution of the portal vein cancer embolus and thrombosis were observed, the collateral vessels accompanied by the portal vein cancer embolus and thrombosis were analyzed too. The statistics analyses were made for the attenuation between the cancer embolus and thrombosis on pre- and post-contrast multi- phase enhancement scanning. Results The portal vein cancer embolus was presented as hypodensity onpre-contrast enhancement scanning accompanied by the portal vein diameter dilated in 12 of 18 cases, it showed as isodensity in the other 6 cases. The cancer embolus was enhanced as hyperdensity on arterial phase in all 18 cases, and its supply arteries were also detected in 15 cases, the cancer embolus appeared as hyperdensity, isodensity and hypodensity on portal venous phase in 4, 5 and 9 cases respectively, it all showed as hypodensity in delay phase. The cancer embolus involved in portal right and/or left branch in all 18 cases, it extended to main branch of portal in only 6 cases. The thrombosis was appeared as isodensity, hypodensity and slightly hyperdensity on pre-contrast enhancement scanning in 3, 3 and 6 cases respectively, there were no attenuation changed on post-contrast enhancement scanning, and all showed as hypodensity filling defect on portal vein phase and delay phase. The thrombosis involved in the main branch of portal vein in 11 cases, it spread to left or/and right branch of portal vein in 6 cases. There were no statistical significance for the attenuation between the cancer embolus and thrombosis on pre-contrast enhancement scanning and delay phase （ all P values 〉 0.05 ） ; the attenuations of cancer embolus were significant high than those of thrombosis in both artery phase and portal vein phase （ all P values 〈 0.05 ）. The ratio of cancer embolus involved in portal right and （or） lift was significantly higher than that of thrombosis, the ratio of thrombosis involved in main branch of portal vein was significantly higher than that of cancer embolus （ all P values 〈 0.05 ）. Conclusions The imaging features and the correlative lesion of portal vein cancer embolus and portal vein thrombosis can be displayed well by combining MSCT axial imaging and its 3D reconstruction imaging in the patients who suffer from liver cirrhosis, it can provide the clear evidence for the diagnosis of portal vein cancer embolus and thrombosis, and guide appropriate treatment options.