| ObjectiveTo study the imaging quality of portal vein by CT spectroscopy and to evaluate the evaluation of esophagogastric varices by using spectral CT portal vein imaging and the prediction of upper gastrointestinal bleeding,so as to provide important reference value for clinical diagnosis and treatment.MethodsSixty patients with clinically suspected liver lesions in our hospital from Aprilt 2016 to December 2016 were randomly divided into Spectral CT group and conventional CT group with 30 patients in each group.The Spectral CT group Enhanced scan,in which the hepatic parenchyma and arterial phase using conventional spiral scan,portal vein spectral scanning mode,double kVp instantaneous switching;conventional CT group routine liver enhanced scanning.By measuring the CT value and image noise of two groups of hepatic parenchyma and portal vein,the ratio of CNR to the main portal vein was measured by using the liver parenchyma as the background,and the independent sample t-test was used to determine whether the difference between the two groups was statistically significant.Collecting portal hypertension patients who underwent endoscopy and spectral CT liver enhanced phase III examination simultaneously from September 2016 to June 2017.The gastroscope was used as the gold standard for the diagnosis of esophagogastric varices which are graded according light level,medium level and heavy level according to the endoscopic grading standards.Spectral CT diagnosis of esophageal varices in the esophagus was classified according to Kim classification.The diagnoses of esophageal varices by endoscopy and spectral CT are analysed by Kappa consistency test.The best monochromatic images of portal vein obtained from patients with portal vein pressure were processed for volume rendering(VR)and maximum density projection(MIP),and the PV proximal and distal diameters,LPV,RPV SV,SMV and LGV diameters were measured.According to the presence or absence of a history of esophageal variceal bleeding,the patients were divided into hemorrhage group and non-hemorrhage group.The difference of portal vein and its related branches between hemorrhage group and non-hemorrhage group was statistically significant.Application of ROC curve to explore the esophageal varices bleeding associated with the highest branch of the portal vein.Evaluate the risk of upper gastrointestinal bleeding in portal hypertension.Results(1)The energy level of the optimal contrast to noise ratio(CNR)for portal vein was about 50 keV.The CNR of portal vein imaging between spectral CT group and conventional CT group were 8.63 ± 1.53 and 3.96 ± 1.72 respectively,and the image quality scores were 4.26 ± 0.739 and 3.20 ± 0.714 respectively.The CNR and image quality scores of the spectral CT group were significantly higher than those of the conventional CT group(P<0.05).?(2)Spectral CT imaging for portal vein and gastroscopy diagnosis ofesophagogastric varices by Kappa test showed good consistency.The Kappa value was 0.826.(3)The diameters of proximal MPV,distal MPV,LPV,SV and LGV were statistically significant between hemorrhage group and non-hemorrhage group(P<0.05).(4)In the prediction of EVB,the sensitivity was 76.92%,the specificity was85.71%,the AUC was 0.846 when the LGV>6.1mm which could be used as an index to predict the esophageal variceal bleeding.Conclusion(1)Compared to conventional CT imaging,the optimal monochromatic CT imaging bothcan significantly improve the image quality of portal vein.(2)There was hight consistence between spectral CT portal venography and the endoscopic in the diagnosis and classification of esophagealgastric varices were diagnosed.(3)Spectral CT imageing for portal vein has a higher clinical value on evaluation of esophageal varices.(4)In spectral CT portal vein imaging,the diameter of gastric left vein can be used as a risk factor for esophageal variceal bleeding. |
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