多层螺旋CT对肝细胞癌合并门静脉癌栓的诊断价值

Value of Multiphasic CT in diagnosis of hepatocellular carcinoma with portal vein thrombosis

目的:探讨多层螺旋CT扫描对肝细胞癌合并门静脉癌栓的诊断价值。材料与方法:回顾性分析25例经手术病理证实的肝细胞癌合并门静脉癌栓患者的三期动态增强CT表现,通过兴趣区(Region of interest,ROI)分析定性和定量评估肿瘤动脉期、静脉期和延迟期图像。另外也通过ROI分析定量评价肝左叶和右叶背景强化情况。结果:定性分析发现40%(10/25)的肝细胞癌表现为动脉期快速不均质血管强化,而64%(16/25)的肿瘤表现为门脉期快速洗脱,另外40%(10/25)的肝细胞癌表现为动脉期快速不均质血管强化和门脉期快速洗脱。定量分析提示动脉期血管强化肝细胞癌从强化前到动脉期的绝对增强值为49.1±17.1HU,而动脉期无血管强化肿瘤为23.8±16.6HU,差异具有统计学意义(P<0.01)。动脉期血管强化肝细胞癌的肝实质背景在动脉期的绝对增强值为13.79±7.9HU,而动脉期无血管强化肿瘤的肝实质背景为36.6±30.6HU,差异具有统计学意义(P=0.03)。结论:很大一部分合并门静脉癌栓的肝细胞癌缺乏特征性的动脉期快速不均质血管强化,可能是背景肝实质动脉血供继发性代偿增加所致,这是应用影像学标准诊断肝细胞癌的一个潜在陷阱。

Purpose： To evaluate the value of multi-slice spiral computed tomography scan in the diagnosis of hepatocellular carcinoma （HCC） with portal vein thrombosis. Materials and Methods： A retrospective study was conducted on the finding of triphasic dynamic contrast enhanced CT scan of 23 patients with hepatocellular carcinoma with portal vein thrombosis. The arterial, portal venous and delayed phase images were assessed qualitatively and quantitatively （ with region of interest [ ROI] analysis） for lesion hypervascularity and washout. The background enhancement of the left and right lobes of the liver was also quantified by ROI analysis. Results： Qualitative analysis showed that 10/25 （40%） lesions demonstrated arterial hypervascularity while 16/25 （64%） lesions showed washout. Ten out of 25 （40%） lesions demonstrated both arterial hypervascularity and washout. Quantitative analysis showed that the average absolute lesion enhancement from precontrast to arterial phases was 49. 1±17. 1 HU for hypervascular lesions compared to 23.8 ±16. 6 HU for non-hypervascular lesions （P 〈0. 01 ）. The mean absolute enhancement of the background liver parenchyma in the arterial phase was 13.79±7.9 HU for hypervaseu- lar lesions compared to 36. 6± 30. 6 HU for non-hypervascular lesions （ P = 0. 03）. Conclusion： A large proportion of HCC with portal vein thrombosis lack characteristic arterial hypervascularity, which may be secondary to compensatory increased arterial supply to the background liver. This is a potential pitfall when applying imaging criteria for diagnosis of HCC.