Evaluation Of LGV In Liver Cirrhosis By Mlti-slice Spiral CT Angiography

Background Formation of portosystemic collateral vessels is an important pathophysiological changes in liver cirrhosis. Left gastric vein(LGV) is one of portosystemic collateral vessels and play an important role in esophageal varices. Researchs of ultrasound show that dilated degree of LGV have a relationship with the degree of cirrhosis and portal vein pressure. Multi-slice spiral CT angiography(MSCTA) provides a new way to observe collateral vessels and can be used to quantitatively analyze the degree of vascular expansion.Purpose Using MSCTA to assess the relationship between the level of liver cirrhosis and the dilated degree of LGV,splenic vein(SV) and portal vein(PV).Materials and Methods A 16-slices spiral CT scanner was used to perform contrast-enhanced abdominal scanning in 36 patients with liver cirrhosis and 19 healthy volunteers(controls). Image post-processing techniques(MIP and VR) were applied to depict LGV and vessels of portal venous system, diameters of PV,SV and LGV were measured.The ANOVA test was applied to assess the difference of these diameters among control group,Child-PughA group and Child-PughBC group;The multiple comparisons was estimated using LSD-t test.25 cirrhosis patients with endoscopy documents were divided into 3 groups: little,modest and large esophageal varices groups;The ANOVA test was applied to assess the difference of vessel diameters among these 3 groups and LSD-t test was used too.In follow-up period,8 patients showed up variceal hemorrhage. Comparisons of vessel diameters between patients with variceal hemorrhage and without variceal hemorrhage used two-sample t-test.Results Excellent image quality of LGV was obtained in all patients with liver cirrhosis and 19 healthy volunteers. The diameters of LGV in Child-PughBC patients are significantly larger than in controls and Child-PughA patients (p=0.002 and 0.015).The diameters of SV in Child-PughA and BCpatients are also significantly larger than in controls (p=0.027 and 0.004),but the diameters of SV have no difference between Child-PughA and BCpatients(p=0.455). The diameters of PV have no difference among controls,Child-PughA and BCpatients(p=0.334).The diameters of LGV in patients with modest esophageal varices are significantly larger than those with little esophageal varices ,and those with large esophageal varices are also significantly larger than those with modest esophageal varices (p=0.02 and 0.026).There are significant differences in diameters of LGV and PV between patients with variceal hemorrhage and without variceal hemorrhage(p=0.015 and 0.036). There are no differences in diameters of SV between patients with variceal hemorrhage and without variceal hemorrhage(p=0.349).Conclusion When using diameters of vessel to evaluate level of liver cirrhosis,LGV is a better index than PV and SV. Measuring diameters of LGV by MSCTA could be used to evaluate liver function and the degree of portal hypertension in cirrhosis patients and to predict the risk of upper gastrointestinal hemorrhage.When diameter of LGV is larger than 6.5mm,the risk of variceal hemorrhage is significantly raises.