Evaluation Of Esophageal Varices In Patients With Liver Cirrhosis By Contrast-enhanced Ultrasonography

ObjectiveTo evaluate the feasibility of evaluating esophageal varices(EV) in liver cirrhosis by contrast-enhanced ultrasonography.MethodsA total of81cases (56esophageal varices patients and25healthy controls without EV) were evaluated by contrast-enhanced ultrasonography(CEUS) for parameters of the lower esophagus, liver parenchyma and renal parenchyma. According to the endoscopy results, we divided those research subjects into three groups. They were light-moderate esophageal varices (L-MEV)-group1, severe esophageal varices (SEV)-group2and the healthy volunteers without EV-group0.(1)56EV patients and25healthy controls were examined by CEUS on the lower esophagus. By means of QLAB software, Time-intensity curves(TIC) of the lower esophagus were obtained. We studied the relationship between CEUS parameters of the lower esophagus and EV grades.Under CEUS, the following parameters of the lower esophagus were measured:①Tm--thickness of double-layers mucosa and submucosa in the lower esophagus.②De--the maximum anteroposterior diameter of the lower esophagus③Tm/De--the ratio of Tm and De④Time-intensity curves(TICs) of the lower esophagus can be drawn through QLAB software.The following4parameters could be calculated from TIC. They were Tes--time to start enhancement of esophagus, Tep--time to peak of the lower esophagus, Iep--peak intensity of the lower esophagus and Tepr(Tepr=Tep-Tes)--relative peak time of the lower esophagus.⑤TIC of abdominal aorta:There were also4parameters could be gotten from TIC. They were Tas--time to start enhancement of abdominal aorta, Tap--time to peak of abdominal aorta, lap--peak intensity of abdominal aorta and Tapr(Tapr=Tap-Tas)--relative peak time of abdominal aorta.⑥Tepr/Tapr-the ratio of Tepr and Tapr.⑥Iep/lap--the ratio of Iep and lap.(2)56EV patients and25healthy controls were examined by CEUS on liver parenchyma. By means of QLAB software, Time-intensity curves(TIC) of the lower esophagus were obtained.We studied the relationship between CEUS parameters of liver parenchyma and EV grades.The following parameters of liver parenchyma were measured:TIC of liver parenchyma were drawn through QLAB software.We got10CEUS parameters from TIC. They were Thap--time to peak of hepatic artery, Ihap--peak intensity of hepatic artery, Tppeak--Time to peak of liver parenchyma, Ippeak--Peak intensity of liver parenchyma,Tpp (Tpp=Tppeak-Thap)--Time to peak of hepatic artery, Ipp(Ipp=Ippeak-Ihap)--Peak intensity of hepatic portal vein, Ipp/Ihap--the ratio of Ipp and Ihap,Tpp/Thap--the ratio of Tpp and Thap,Ipp/Ipeak--the ratio of Ipp and Ipeak and Tpp/Tpeak--the ratio of Tpp and Tpeak.Spearman rank correlation was used to study the correlation between CEUS and EV grades. One factor analysis of variance was used to compare means between3groups. Compare CEUS parameters of liver between G1and G2with two-sample t-test. And the diagnostic value of CEUS was assessed by receiver operating characteristic (ROC) curves.Bayes discriminant analysis was adopted for building discriminant equation.Results1.Results of correlative analysis of CEUS and grades of EV(1)Tm, De, Tm/De, Tepr and Iep/Iap were correlated with the severity of esophageal varices.Among these, Tm(r=0.910, p=0.000) and De (r=0.837, p=0.000) had notable correlation with the grades of EV.(2)There were no correlation between the CEUS parameters of liver parenchyma and the severity of EV.2. Results of comparison of CEUS parameters between different EV groups:(1)Tm, De, Tm/De, Tepr and Iep/Iap were greater in patients with esophageal varices(G1and G2) than that of people without EV(GO). Tm and De had statistically difference between any two groups among G0, G1and G2.(2)The CEUS parameters of liver were not different in G1and G2(p>0.1).3.The sensitivity and specificity of the diagnosis of G2of Tm, De, Tm/De, Tepr, Iep/Iap respectively were93.8%,90.6%,78.1%,96.6%,82.8%and95%,72.5%,80%,37.8%,67.7%. Among them, Tm and De enjoyed higher sensitivity and specificity.4.Three discriminant equations were got from Bayes discriminant analysis. They were yo=-6.2+2.5Tm, y1=-15.1+4.1Tm and y2=-31.7+6.0Tm,respectively. The equations correctly classified91.7%cases of the population. The error rate were8.3%.ConclusionTm and De attained from CEUS had significant positive relation with the grades of EV. They were different between any two groups. And Tm and De enjoyed high sensitivity and specificity in diagnosing severe esophageal varices (G2). The discriminant equations correctly classified91.7%cases of our study objects. The error rate were8.3%. Therefore we supposed that CEUS can be a new, convenient, noinvasive parameters for diagnosing the severity esophageal varices in liver cirrhotic patients.