门静脉系统血栓及其继发性病变的多层CT诊断价值

The role of multi-slice CT in portal vein thrombosis

目的探讨门脉系统血栓及其继发性病变的多层CT表现。方法回顾性分析经手术病理证实或经临床综合诊断的37例门脉系统血栓患者的多层CT表现,分析门脉血栓及肝内外继发性病变的CT表现特征,并与50例经病理证实的肝癌门脉癌栓做对照。结果门脉血栓的直接征象:除3例机化性血栓外,其余34例血栓边缘光滑、界限清楚、形态规则,局部门脉管壁见线样强化征,而所有癌栓未见线样强化征;动脉期血栓平均强化(9.32±5.32)Hu,与癌栓(43.08±14.05)Hu比较具有显著性差异(t=15.59,P<0.01);动脉期所有血栓未见强化血管影,而19/50例癌栓见肿瘤滋养动脉影;此外,癌栓更易导致管腔完全性阻塞(癌栓组100%,血栓组32.43%)和门静脉管腔显著扩张(癌栓组68.00%,血栓组8.11%)。门脉血栓继发性病变包括:①肝实质缺血4例;②肝动脉灌注增加14例:门脉主干栓塞者以外周带为主(9/10),分支栓塞者按肝叶或肝段分布(4/4);③门脉海绵样变7例:④肠壁淤血水肿4例;⑤脾脏淤血性损伤4例。结论多层CT对诊断门脉系统血栓具有特征性,能与癌栓鉴别,并进一步反映肝内外继发性病变,对临床制定治疗方案具有重要意义。

Objective To discuss the imaging features of portal vein system thrombosis and its secondary changes in multi-slice CT examination. Methods By contrast with the CT features of tumor thrombus in portal vein system in 50 cases which confirmed by histopathology, we retrospectively analyzed the dynamic enhancement CT features of venous throm-bosis in portal vein system and its secondary changes in 37 consecutive patients, who were diagnosed by histopathology or clinic data combined with imaging follow-up more than 6 months. Results Except for chronic organized thrombus in 3 cases, in all the other 34 cases, benign thrombus in portal vein system （34/37, 91.89%） had smooth edge, clear border and regular contour. The related portal wall presented distinct linear enhancement in those cases. While in tumor thrombus group, we couldn＇t found linear enhancement on the related portal wall. In contrast-enhanced hepatic arterial phase the mean enhancement of these 34 benign thrombus was （9.32 ± 5.32） Hu, which had a significant difference from that of tumor thrombus （[43.08±14.05] Hu） （t=15.59, P〈0.01）. In hepatic arterial phase, none of benign thrombus presented enhanced vessel branches; while enhanced nutrient arterial branches could be found in 19 tumor thrombus （19/50, 38.00%）. Besides these, tumor thrombus was incident to cause complete block （100% in tumor thrombus, 32.43% in benign thrombus） and significant dilatation of portal vein （68.00% in tumor thrombus, 8.11% in benign thrombus）. The second-ary changes of portal vein system thrombosis included hepatic parenchyma ischemia in 4 cases, abnormal hepatic perfusion in 14 cases, cavernous transformation of portal vein in 7 cases, acute congestive edema and necrosis of intestinal wall in 3 cases and splenic congestive injury in 4 cases. 9 patients with thrombosis in the main trunk of portal vein presented hyper- perfusion areas in the peripheral part of liver in hepatic arterial phase （9/10）; the other one had hyper-perfusion in the whole liver. While all the patients with thrombosis in portal vein branches （4/4） had hyper-perfusion areas in the involved lobe or segment. Conclusion The imaging features of benign thrombosis in portal vein system in multi-slice CT exam are of characteristic, which differentiate from tumor thrombus. And the secondary changes could be estimated in CT exam. So we believe multi-slice CT examination could supply useful information in guiding clinical treatment for portal vein system thrombosis.